Table of Contents
graph - 2D graph for plotting X-Y coordinate
data.
graph pathName ?option value ?...
The graph
command creates a graph for plotting two-dimensional data (X-Y coordinates).
It has many configurable components: coordinate axes, elements, legend,
grid lines, cross hairs, etc. They allow you to customize the look and
feel of the graph.
The graph command creates a new window
for plotting two-dimensional data (X-Y coordinates). Data points are plotted
in a rectangular area displayed in the center of the new window. This
is the plotting area . The coordinate axes are drawn in the margins around
the plotting area. By default, the legend is displayed in the right margin.
The title is displayed in top margin.
The graph widget is composed of
several components: coordinate axes, data elements, legend, grid, cross
hairs, pens, postscript, and annotation markers.
- axis
- The graph has
four standard axes (x , x2 , y , and y2 ), but you can create and display
any number of axes. Axes control what region of data is displayed and
how the data is scaled. Each axis consists of the axis line, title, major
and minor ticks, and tick labels. Tick labels display the value at each
major tick.
- crosshairs
- Cross hairs are used to position the mouse pointer
relative to the X and Y coordinate axes. Two perpendicular lines, intersecting
at the current location of the mouse, extend across the plotting area
to the coordinate axes.
- element
- An element represents a set of data
points. Elements can be plotted with a symbol at each data point and lines
connecting the points. The appearance of the element, such as its symbol,
line width, and color is configurable.
- grid
- Extends the major and minor
ticks of the X-axis and/or Y-axis across the plotting area.
- legend
- The
legend displays the name and symbol of each data element. The legend can
be drawn in any margin or in the plotting area.
- marker
- Markers are used
annotate or highlight areas of the graph. For example, you could use a
polygon marker to fill an area under a curve, or a text marker to label
a particular data point. Markers come in various forms: text strings,
bitmaps, connected line segments, images, polygons, or embedded widgets.
- pen
- Pens define attributes (both symbol and line style) for elements.
Data elements use pens to specify how they should be drawn. A data element
may use many pens at once. Here, the particular pen used for a data point
is determined from each element's weight vector (see the element's -weight
and -style options).
- postscript
- The widget can generate encapsulated
PostScript output. This component has several options to configure how
the PostScript is generated.
graph pathName ?option value ?...
The graph command creates a new window pathName and makes it into a
graph widget. At the time this command is invoked, there must not exist
a window named pathName , but pathName 's parent must exist. Additional
options may be specified on the command line or in the option database
to configure aspects of the graph such as its colors and font. See the
configure operation below for the exact details about what option and
value pairs are valid.
If successful, graph returns the path name of
the widget. It also creates a new Tcl command by the same name. You can
use this command to invoke various operations that query or modify the
graph. The general form is:
pathName operation ?arg ?...
Both operation
and its arguments determine the exact behavior of the command. The operations
available for the graph are described in the GRAPH OPERATIONS
section.
The command can also be used to access components of the graph.
pathName
component operation ?arg ?...
The operation, now located after the name
of the component, is the function to be performed on that component. Each
component has its own set of operations that manipulate that component.
They will be described below in their own sections.
The graph
command creates a new graph.
# Create a new graph. Plotting area is
black.
graph .g -plotbackground black
A new Tcl command .g is also created.
This command can be used to query and modify the graph. For example,
to change the title of the graph to "My Plot", you use the new command
and the graph's configure operation.
# Change the title.
.g configure
-title "My Plot"
A graph has several components. To access a particular
component you use the component's name. For example, to add data elements,
you use the new command and the element component.
# Create a new element
named "line1"
.g element create line1 \
-xdata { 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
1.8 2.0 } \
-ydata { 26.18 50.46 72.85 93.31 111.86 128.47 143.14
155.85 166.60
175.38 }
The element's X-Y coordinates are specified using lists of numbers.
Alternately, BLT vectors could be used to hold the X-Y coordinates.
#
Create two vectors and add them to the graph.
vector xVec yVec
xVec set
{ 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 }
yVec set { 26.18 50.46 72.85 93.31 111.86
128.47 143.14 155.85
166.60 175.38 }
.g element create line1 -xdata xVec -ydata
yVec
The advantage of using vectors is that when you modify one, the
graph is automatically redrawn to reflect the new values.
# Change the
y coordinate of the first point.
set yVector(0) 25.18
An element named
e1 is now created in .b . It is automatically added to the display list
of elements. You can use this list to control in what order elements are
displayed. To query or reset the element display list, you use the element's
show operation.
# Get the current display list
set elemList [.b element
show]
# Remove the first element so it won't be displayed.
.b element show
[lrange $elemList 0 end]
The element will be displayed by as many bars
as there are data points (in this case there are ten). The bars will be
drawn centered at the x-coordinate of the data point. All the bars will
have the same attributes (colors, stipple, etc). The width of each bar
is by default one unit. You can change this with using the -barwidth option.
# Change the X-Y coordinates of the first point.
set xVec(0) 0.18
set
yVec(0) 25.18
An element named line1 is now created in .g . By default,
the element's label in the legend will be also line1 . You can change the
label, or specify no legend entry, again using the element's configure
operation.
# Don't display "line1" in the legend.
.g element configure
line1 -label ""
You can configure more than just the element's label. An
element has many attributes such as symbol type and size, dashed or solid
lines, colors, line width, etc.
.g element configure line1 -symbol square
-color red \
-dashes { 2 4 2 } -linewidth 2 -pixels 2c
Four coordinate axes
are automatically created: x , x2 , y , and y2 . And by default, elements
are mapped onto the axes x and y . This can be changed with the -mapx
and -mapy options.
# Map "line1" on the alternate Y-axis "y2".
.g element
configure line1 -mapy y2
Axes can be configured in many ways too. For
example, you change the scale of the Y-axis from linear to log using the
axis component.
# Y-axis is log scale.
.g axis configure y -logscale yes
One important way axes are used is to zoom in on a particular data region.
Zooming is done by simply specifying new axis limits using the -min and
-max configuration options.
.g axis configure x -min 1.0 -max 1.5
.g axis
configure y -min 12.0 -max 55.15
To zoom interactively, you link the axis
configure operations with some user interaction (such as pressing the
mouse button), using the bind command. To convert between screen and
graph coordinates, use the invtransform operation.
# Click the button
to set a new minimum
bind .g <ButtonPress-1> {
%W axis configure x
-min [%W axis invtransform x %x]
%W axis configure x -min [%W axis
invtransform x %y]
}
By default, the limits of the axis are determined
from data values. To reset back to the default limits, set the -min and
-max options to the empty value.
# Reset the axes to autoscale again.
.g axis configure x -min {} -max {}
.g axis configure y -min {} -max {}
By
default, the legend is drawn in the right margin. You can change this
or any legend configuration options using the legend component.
# Configure
the legend font, color, and relief
.g legend configure -position left -relief
raised \
-font fixed -fg blue
To prevent the legend from being displayed,
turn on the -hide option.
# Don't display the legend.
.g legend configure
-hide yes
The graph widget has simple drawing procedures called markers.
They can be used to highlight or annotate data in the graph. The types
of markers available are bitmaps, images, polygons, lines, or windows.
Markers can be used, for example, to mark or brush points. In this example,
is a text marker that labels the data first point. Markers are created
using the marker component.
# Create a label for the first data point
of "line1".
.g marker create text -name first_marker -coords { 0.2 26.18 }
\
-text "start" -anchor se -xoffset -10 -yoffset -10
This creates a text marker
named first_marker . It will display the text "start" near the coordinates
of the first data point. The -anchor , -xoffset , and -yoffset options are
used to display the marker above and to the left of the data point, so
that the data point isn't covered by the marker. By default, markers are
drawn last, on top of data. You can change this with the -under option.
# Draw the label before elements are drawn.
.g marker configure first_marker
-under yes
You can add cross hairs or grid lines using the crosshairs
and grid components.
# Display both cross hairs and grid lines.
.g crosshairs
configure -hide no -color red
.g grid configure -hide no -dashes { 2 2 }
Finally, to get hardcopy of the graph, use the postscript component.
# Print the graph into file "file.ps"
.g postscript output file.ps -maxpect
yes -decorations no
This generates a file file.ps containing the encapsulated
PostScript of the graph. The option -maxpect says to scale the plot to
the size of the page. Turning off the -decorations option denotes that
no borders or color backgrounds should be drawn (i.e. the background of
the margins, legend, and plotting area will be white).
- pathName axis operation ?arg ?...
- See the AXIS COMPONENTS
section.
- pathName
bar elemName ?option value ?...
- Creates a new barchart element elemName
. It's an error if an element elemName already exists. See the manual
for barchart for details about what option and value pairs are valid.
- pathName cget option
- Returns the current value of the configuration
option given by option . Option may be any option described below for
the configure operation.
- pathName configure ?option value ?...
- Queries
or modifies the configuration options of the graph. If option isn't specified,
a list describing the current options for pathName is returned. If option
is specified, but not value , then a list describing option is returned.
If one or more option and value pairs are specified, then for each pair,
the option option is set to value . The following options are valid.
- -background
color
- Sets the background color. This includes the margins and legend,
but not the plotting area.
- -borderwidth pixels
- Sets the width of the 3-D
border around the outside edge of the widget. The -relief option determines
if the border is to be drawn. The default is 2 .
- -bottommargin pixels
- If non-zero, overrides the computed size of the margin extending below
the X-coordinate axis. If pixels is 0 , the automatically computed size
is used. The default is 0 .
- -bufferelements boolean
- Indicates whether
an internal pixmap to buffer the display of data elements should be used.
If boolean is true, data elements are drawn to an internal pixmap. This
option is especially useful when the graph is redrawn frequently while
the remains data unchanged (for example, moving a marker across the plot).
See the SPEED TIPS
section. The default is 1 .
- -cursor cursor
- Specifies
the widget's cursor. The default cursor is crosshair .
- -font fontName
- Specifies the font of the graph title. The default is *-Helvetica-Bold-R-Normal-*-18-180-*
.
- -halo pixels
- Specifies a maximum distance to consider when searching
for the closest data point (see the element's closest operation below).
Data points further than pixels away are ignored. The default is 0.5i
.
- -height pixels
- Specifies the requested height of widget. The default
is 4i .
- -invertxy boolean
- Indicates whether the placement X-axis and Y-axis
should be inverted. If boolean is true, the X and Y axes are swapped.
The default is 0 .
- -justify justify
- Specifies how the title should be
justified. This matters only when the title contains more than one line
of text. Justify must be left , right , or center . The default is center
.
- -leftmargin pixels
- If non-zero, overrides the computed size of the margin
extending from the left edge of the window to the Y-coordinate axis.
If pixels is 0 , the automatically computed size is used. The default
is 0 .
- -plotbackground color
- Specifies the background color of the plotting
area. The default is white .
- -plotborderwidth pixels
- Sets the width of
the 3-D border around the plotting area. The -plotrelief option determines
if a border is drawn. The default is 2 .
- -plotpadx pad
- Sets the amount
of padding to be added to the left and right sides of the plotting area.
Pad can be a list of one or two screen distances. If pad has two elements,
the left side of the plotting area entry is padded by the first distance
and the right side by the second. If pad is just one distance, both the
left and right sides are padded evenly. The default is 8 .
- -plotpady pad
- Sets the amount of padding to be added to the top and bottom of the
plotting area. Pad can be a list of one or two screen distances. If pad
has two elements, the top of the plotting area is padded by the first
distance and the bottom by the second. If pad is just one distance, both
the top and bottom are padded evenly. The default is 8 .
- -plotrelief relief
- Specifies the 3-D effect for the plotting area. Relief specifies how
the interior of the plotting area should appear relative to rest of the
graph; for example, raised means the plot should appear to protrude from
the graph, relative to the surface of the graph. The default is sunken
.
- -relief relief
- Specifies the 3-D effect for the graph widget. Relief
specifies how the graph should appear relative to widget it is packed
into; for example, raised means the graph should appear to protrude.
The default is flat .
- -rightmargin pixels
- If non-zero, overrides the computed
size of the margin extending from the plotting area to the right edge
of the window. By default, the legend is drawn in this margin. If pixels
is 0 , the automatically computed size is used. The default is 0 .
- -takefocus
focus
- Provides information used when moving the focus from window
to window via keyboard traversal (e.g., Tab and Shift-Tab). If focus is
0 , this means that this window should be skipped entirely during keyboard
traversal. 1 means that the this window should always receive the input
focus. An empty value means that the traversal scripts make the decision
whether to focus on the window. The default is "" .
- -tile image
- Specifies
a tiled background for the widget. If image isn't "" , the background
is tiled using image . Otherwise, the normal background color is drawn
(see the -background option). Image must be an image created using the
Tk image command. The default is "" .
- -title text
- Sets the title to
text . If text is "" , no title will be displayed.
- -topmargin pixels
- If non-zero, overrides the computed size of the margin above the x2 axis.
If pixels is 0 , the automatically computed size is used. The default
is 0 .
- -width pixels
- Specifies the requested width of the widget. The
default is 5i .
- pathName crosshairs operation ?arg ?
- See the CROSSHAIRS
COMPONENT
section.
- pathName element operation ?arg ?...
- See the ELEMENT
COMPONENTS
section.
- pathName extents item
- Returns the size of a particular
item in the graph. Item must be either leftmargin , rightmargin , topmargin
, bottommargin , plotwidth , or plotheight .
- pathName grid operation ?arg
?...
- See the GRID COMPONENT
section.
- pathName invtransform winX winY
- Performs an inverse coordinate transformation, mapping window coordinates
back to graph coordinates, using the standard X-axis and Y-axis. Returns
a list of containing the X-Y graph coordinates.
- pathName inside x y
- Returns
1 is the designated screen coordinate (x and y ) is inside the plotting
area and 0 otherwise.
- pathName legend operation ?arg ?...
- See the LEGEND
COMPONENT
section.
- pathName line operation arg ...
- The operation is the
same as element .
- pathName marker operation ?arg ?...
- See the MARKER COMPONENTS
section.
- pathName postscript operation ?arg ?...
- See the POSTSCRIPT COMPONENT
section.
- pathName snap photoName
- Takes a snapshot of the graph and
stores the contents in the photo image photoName . PhotoName is the name
of a Tk photo image that must already exist.
- pathName transform x y
- Performs a coordinate transformation, mapping graph coordinates to window
coordinates, using the standard X-axis and Y-axis. Returns a list containing
the X-Y screen coordinates.
- pathName xaxis operation ?arg ?...
- pathName x2axis
operation ?arg ?...
- pathName yaxis operation ?arg ?...
- pathName y2axis
operation ?arg ?...
- See the AXIS COMPONENTS
section.
A graph is composed of several components: coordinate axes, data elements,
legend, grid, cross hairs, postscript, and annotation markers. Instead
of one big set of configuration options and operations, the graph is partitioned,
where each component has its own configuration options and operations
that specifically control that aspect or part of the graph.
Four coordinate axes are automatically created: two X-coordinate axes (x
and x2 ) and two Y-coordinate axes (y , and y2 ). By default, the axis
x is located in the bottom margin, y in the left margin, x2 in the
top margin, and y2 in the right margin.
An axis consists of the axis line,
title, major and minor ticks, and tick labels. Major ticks are drawn at
uniform intervals along the axis. Each tick is labeled with its coordinate
value. Minor ticks are drawn at uniform intervals within major ticks.
The range of the axis controls what region of data is plotted. Data points
outside the minimum and maximum limits of the axis are not plotted. By
default, the minimum and maximum limits are determined from the data,
but you can reset either limit.
You can have several axes. To create an
axis, invoke the axis component and its create operation.
# Create a
new axis called "tempAxis"
.g axis create tempAxis
You map data elements
to an axis using the element's -mapy and -mapx configuration options. They
specify the coordinate axes an element is mapped onto.
# Now map the
tempAxis data to this axis.
.g element create "e1" -xdata $x -ydata $y -mapy
tempAxis
Any number of axes can be displayed simultaneously. They are
drawn in the margins surrounding the plotting area. The default axes x
and y are drawn in the bottom and left margins. The axes x2 and y2
are drawn in top and right margins. By default, only x and y are shown.
Note that the axes can have different scales.
To display a different axis
or more than one axis, you invoke one of the following components: xaxis
, yaxis , x2axis , and y2axis . Each component has a use operation that
designates the axis (or axes) to be drawn in that corresponding margin:
xaxis in the bottom, yaxis in the left, x2axis in the top, and y2axis
in the right.
# Display the axis tempAxis in the left margin.
.g yaxis
use tempAxis
The use operation takes a list of axis names as its last
argument. This is the list of axes to be drawn in this margin.
You can
configure axes in many ways. The axis scale can be linear or logarithmic.
The values along the axis can either monotonically increase or decrease.
If you need custom tick labels, you can specify a Tcl procedure to format
the label any way you wish. You can control how ticks are drawn, by changing
the major tick interval or the number of minor ticks. You can define non-uniform
tick intervals, such as for time-series plots.
- pathName axis cget axisName
option
- Returns the current value of the option given by option for
axisName . Option may be any option described below for the axis configure
operation.
- pathName axis configure axisName ?axisName ?... ?option value
?...
- Queries or modifies the configuration options of axisName . Several
axes can be changed. If option isn't specified, a list describing all
the current options for axisName is returned. If option is specified,
but not value , then a list describing option is returned. If one or
more option and value pairs are specified, then for each pair, the axis
option option is set to value . The following options are valid for axes.
- -autorange range
- Sets the range of values for the axis to range . The
axis limits are automatically reset to display the most recent data points
in this range. If range is 0.0, the range is determined from the limits
of the data. If -min or -max are specified, they override this option.
The default is 0.0 .
- -color color
- Sets the color of the axis and tick
labels. The default is black .
- -command prefix
- Specifies a Tcl command
to be invoked when formatting the axis tick labels. Prefix is a string
containing the name of a Tcl proc and any extra arguments for the procedure.
This command is invoked for each major tick on the axis. Two additional
arguments are passed to the procedure: the pathname of the widget and
the current the numeric value of the tick. The procedure returns the formatted
tick label. If "" is returned, no label will appear next to the tick.
You can get the standard tick labels again by setting prefix to "" .
The default is "" .
Please note that this procedure is invoked while
the graph is redrawn. You may query configuration options. But do not them,
because this can have unexpected results.
- -descending boolean
- Indicates
whether the values along the axis are monotonically increasing or decreasing.
If boolean is true, the axis values will be decreasing. The default
is 0 .
- -hide string
- Indicates if the axis and all the elements mapped
to it will be displayed. The valid values for string are shown below.
The default value is 0 .
- false
- The axis and its data elements are displayed.
- true
- The axis is hidden, but the data elements mapped to it are displayed.
- all
- The axis and its data elements are hidden.
- -justify justify
- Specifies
how the axis title should be justified. This matters only when the axis
title contains more than one line of text. Justify must be left , right
, or center . The default is center .
- -limits formatStr
- Specifies a printf-like
description to format the minimum and maximum limits of the axis. The
limits are displayed at the top/bottom or left/right sides of the plotting
area. FormatStr is a list of one or two format descriptions. If one description
is supplied, both the minimum and maximum limits are formatted in the
same way. If two, the first designates the format for the minimum limit,
the second for the maximum. If "" is given as either description, then
the that limit will not be displayed. The default is "" .
- -linewidth pixels
- Sets the width of the axis and tick lines. The default is 1 pixel.
- -logscale
boolean
- Indicates whether the scale of the axis is logarithmic or linear.
If boolean is true, the axis is logarithmic. The default scale is linear.
- -loose boolean
- Indicates whether the limits of the axis should fit the
data points tightly, at the outermost data points, or loosely, at the
outer tick intervals. If the axis limit is set with the -min or -max option,
the axes are displayed tightly. If boolean is true, the axis range is
"loose". The default is 0 .
- -majorticks majorList
- Specifies where to display
major axis ticks. You can use this option to display ticks at non-uniform
intervals. MajorList is a list of axis coordinates designating the location
of major ticks. No minor ticks are drawn. If majorList is "" , major
ticks will be automatically computed. The default is "" .
- -max value
- Sets
the maximum limit of axisName . Any data point greater than value is
not displayed. If value is "" , the maximum limit is calculated using
the largest data value. The default is "" .
- -min value
- Sets the minimum
limit of axisName . Any data point less than value is not displayed.
If value is "" , the minimum limit is calculated using the smallest data
value. The default is "" .
- -minorticks minorList
- Specifies where to display
minor axis ticks. You can use this option to display minor ticks at non-uniform
intervals. MinorList is a list of real values, ranging from 0.0 to 1.0,
designating the placement of a minor tick. No minor ticks are drawn if
the -majortick option is also set. If minorList is "" , minor ticks will
be automatically computed. The default is "" .
- -rotate theta
- Specifies
the how many degrees to rotate the axis tick labels. Theta is a real value
representing the number of degrees to rotate the tick labels. The default
is 0.0 degrees.
- -showticks boolean
- Indicates whether axis ticks should
be drawn. If boolean is true, ticks are drawn. If false, only the axis
line is drawn. The default is 1 .
- -stepsize value
- Specifies the interval
between major axis ticks. If value isn't a valid interval (must be less
than the axis range), the request is ignored and the step size is automatically
calculated.
- -subdivisions number
- Indicates how many minor axis ticks
are to be drawn. For example, if number is two, only one minor tick is
drawn. If number is one, no minor ticks are displayed. The default is
2 .
- -tickfont fontName
- Specifies the font for axis tick labels. The default
is *-Courier-Bold-R-Normal-*-100-* .
- -ticklength pixels
- Sets the length of major
and minor ticks (minor ticks are half the length of major ticks). If pixels
is less than zero, the axis will be inverted with ticks drawn pointing
towards the plot. The default is 0.1i .
- -title text
- Sets the title of the
axis. If text is "" , no axis title will be displayed.
- -titlecolor color
- Sets the color of the axis title. The default is black .
- -titlefont fontName
- Specifies the font for axis title. The default is *-Helvetica-Bold-R-Normal-*-14-140-*
.
Axis configuration options may be also be set by the option command.
The resource class is Axis . The resource names are the names of the
axes (such as x or x2 ).
option add *Graph.Axis.Color blue
option add
*Graph.x.LogScale true
option add *Graph.x2.LogScale false
- pathName axis
create axisName ?option value ?...
- Creates a new axis by the name axisName
. No axis by the same name can already exist. Option and value are described
in above in the axis configure operation.
- pathName axis delete ?axisName
?...
- Deletes the named axes. An axis is not really deleted until it is not
longer in use, so it's safe to delete axes mapped to elements.
- pathName
axis invtransform axisName value
- Performs the inverse transformation,
changing the screen coordinate value to a graph coordinate, mapping the
value mapped to axisName . Returns the graph coordinate.
- pathName axis
limits axisName
- Returns a list of the minimum and maximum limits for
axisName . The order of the list is min max .
- pathName axis names ?pattern
?...
- Returns a list of axes matching zero or more patterns. If no pattern
argument is give, the names of all axes are returned.
- pathName axis transform
axisName value
- Transforms the coordinate value to a screen coordinate
by mapping the it to axisName . Returns the transformed screen coordinate.
The default axes are x , y , x2 , and y2 . But you can display more than
four axes simultaneously. You can also swap in a different axis with use
operation of the special axis components: xaxis , x2axis , yaxis , and
y2axis .
.g create axis temp
.g create axis time
...
.g xaxis use temp
.g yaxis use time
Only the axes specified for use are displayed on the
screen.
The xaxis , x2axis , yaxis , and y2axis components operate on
an axis location rather than a specific axis like the more general axis
component does. They implicitly control the axis that is currently using
to that location. By default, xaxis uses the x axis, yaxis uses y ,
x2axis uses x2 , and y2axis uses y2 . When more than one axis is displayed
in a margin, it represents the first axis displayed.
The following operations
are available for axes. They mirror exactly the operations of the axis
component. The axis argument must be xaxis , x2axis , yaxis , or y2axis
. This feature is deprecated since more than one axis can now be used
a margin. You should only use the xaxis , x2axis , yaxis , and y2axis
components with the use operation. For all other operations, use the
general axis component instead.
- pathName axis cget option
- pathName axis
configure ?option value ?...
- pathName axis invtransform value
- pathName
axis limits
- pathName axis transform value
- pathName axis use ?axisName
?
- Designates the axis axisName is to be displayed at this location.
AxisName can not be already in use at another location. This command
returns the name of the axis currently using this location.
Cross hairs consist of two intersecting lines (one vertical
and one horizontal) drawn completely across the plotting area. They are
used to position the mouse in relation to the coordinate axes. Cross hairs
differ from line markers in that they are implemented using XOR drawing
primitives. This means that they can be quickly drawn and erased without
redrawing the entire graph.
The following operations are available for
cross hairs:
- pathName crosshairs cget option
- Returns the current value
of the cross hairs configuration option given by option . Option may
be any option described below for the cross hairs configure operation.
- pathName crosshairs configure ?option value ?...
- Queries or modifies
the configuration options of the cross hairs. If option isn't specified,
a list describing all the current options for the cross hairs is returned.
If option is specified, but not value , then a list describing option
is returned. If one or more option and value pairs are specified, then
for each pair, the cross hairs option option is set to value . The following
options are available for cross hairs.
- -color color
- Sets the color of
the cross hairs. The default is black .
- -dashes dashList
- Sets the dash
style of the cross hairs. DashList is a list of up to 11 numbers that
alternately represent the lengths of the dashes and gaps on the cross
hair lines. Each number must be between 1 and 255. If dashList is ""
, the cross hairs will be solid lines.
- -hide boolean
- Indicates whether
cross hairs are drawn. If boolean is true, cross hairs are not drawn.
The default is yes .
- -linewidth pixels
- Set the width of the cross hair
lines. The default is 1 .
- -position pos
- Specifies the screen position
where the cross hairs intersect. Pos must be in the form "@x,y ", where
x and y are the window coordinates of the intersection.
Cross hairs configuration
options may be also be set by the option command. The resource name and
class are crosshairs and Crosshairs respectively.
option add *Graph.Crosshairs.LineWidth
2
option add *Graph.Crosshairs.Color red
- pathName crosshairs off
- Turns off the cross hairs.
- pathName crosshairs on
- Turns on the display
of the cross hairs.
- pathName crosshairs toggle
- Toggles the current state
of the cross hairs, alternately mapping and unmapping the cross hairs.
A data element represents a set of data. It contains
x and y vectors containing the coordinates of the data points. Elements
can be displayed with a symbol at each data point and lines connecting
the points. Elements also control the appearance of the data, such as
the symbol type, line width, color etc.
When new data elements are created,
they are automatically added to a list of displayed elements. The display
list controls what elements are drawn and in what order.
The following
operations are available for elements.
- pathName element activate elemName
?index ?...
- Specifies the data points of element elemName to be drawn
using active foreground and background colors. ElemName is the name of
the element and index is a number representing the index of the data
point. If no indices are present then all data points become active.
- pathName
element bind tagName ?sequence ? ?command ?
- Associates command with
tagName such that whenever the event sequence given by sequence occurs
for an element with this tag, command will be invoked. The syntax is
similar to the bind command except that it operates on graph elements,
rather than widgets. See the bind manual entry for complete details on
sequence and the substitutions performed on command before invoking
it.
If all arguments are specified then a new binding is created, replacing
any existing binding for the same sequence and tagName . If the first
character of command is + then command augments an existing binding
rather than replacing it. If no command argument is provided then the
command currently associated with tagName and sequence (it's an error
occurs if there's no such binding) is returned. If both command and
sequence are missing then a list of all the event sequences for which
bindings have been defined for tagName .
- pathName element cget elemName
option
- Returns the current value of the element configuration option
given by option . Option may be any of the options described below for
the element configure operation.
- pathName element closest x y varName
?option value ?... ?elemName ?...
- Finds the data point closest to the window
coordinates x and y in the element elemName . ElemName is the name
of an element, that must not be hidden. If no elements are specified,
then all visible elements are searched. It returns via the array variable
varName the name of the closest element, the index of its closest point,
and the graph coordinates of the point. Returns 0 , if no data point within
the threshold distance can be found, otherwise 1 is returned. The following
option -value pairs are available.
- -halo pixels
- Specifies a threshold
distance where selected data points are ignored. Pixels is a valid screen
distance, such as 2 or 1.2i . If this option isn't specified, then it defaults
to the value of the graph's -halo option.
- -interpolate string
- Indicates
whether to consider projections that lie along the line segments connecting
data points when searching for the closest point. The default value is
0 . The values for string are described below.
- no
- Search only for the
closest data point.
- yes
- Search includes projections that lie along the
line segments connecting the data points.
- x
- Search includes vertical
projections from the given X-coordinate.
- y
- Search includes horizontal
projections from the given Y-coordinate.
- pathName element configure elemName
?elemName ... ?option value ?...
- Queries or modifies the configuration options
for elements. Several elements can be modified at the same time. If option
isn't specified, a list describing all the current options for elemName
is returned. If option is specified, but not value , then a list describing
the option option is returned. If one or more option and value pairs
are specified, then for each pair, the element option option is set to
value . The following options are valid for elements.
- -activepen penName
- Specifies pen to use to draw active element. If penName is "" , no
active elements will be drawn. The default is activeLine .
- -bindtags tagList
- Specifies the binding tags for the element. TagList is a list of binding
tag names. The tags and their order will determine how events for elements.
Each tag in the list matching the current event sequence will have its
Tcl command executed. Implicitly the name of the element is always the
first tag in the list. The default value is all .
- -color color
- Sets the
color of the traces connecting the data points.
- -dashes dashList
- Sets
the dash style of element line. DashList is a list of up to 11 numbers
that alternately represent the lengths of the dashes and gaps on the element
line. Each number must be between 1 and 255. If dashList is "" , the
lines will be solid.
- -data coordList
- Specifies the X-Y coordinates of the
data. CoordList is a list of numeric expressions representing the X-Y
coordinate pairs of each data point.
- -fill color
- Sets the interior color
of symbols. If color is "" , then the interior of the symbol is transparent.
If color is defcolor , then the color will be the same as the -color
option. The default is defcolor .
- -hide boolean
- Indicates whether the
element is displayed. The default is no .
- -label text
- Sets the element's
label in the legend. If text is "" , the element will have no entry in
the legend. The default label is the element's name.
- -linewidth pixels
- Sets the width of the connecting lines between data points. If pixels
is 0 , no connecting lines will be drawn between symbols. The default
is 0 .
- -mapx xAxis
- Selects the X-axis to map the element's X-coordinates
onto. XAxis must be the name of an axis. The default is x .
- -mapy yAxis
- Selects the Y-axis to map the element's Y-coordinates onto. YAxis must
be the name of an axis. The default is y .
- -offdash color
- Sets the color
of the stripes when traces are dashed (see the -dashes option). If color
is "" , then the "off" pixels will represent gaps instead of stripes.
If color is defcolor , then the color will be the same as the -color
option. The default is defcolor .
- -outline color
- Sets the color or the
outline around each symbol. If color is "" , then no outline is drawn.
If color is defcolor , then the color will be the same as the -color
option. The default is defcolor .
- -outlinewidth pixels
- Sets the width
of the outline bordering each symbol. If pixels is 0 , no outline will
be drawn. The default is 1 .
- -pixels pixels
- Sets the size of symbols. If
pixels is 0 , no symbols will be drawn. The default is 0.125i .
- -scalesymbols
boolean
- If boolean is true, the size of the symbols drawn for elemName
will change with scale of the X-axis and Y-axis. At the time this option
is set, the current ranges of the axes are saved as the normalized scales
(i.e scale factor is 1.0) and the element is drawn at its designated size
(see the -pixels option). As the scale of the axes change, the symbol
will be scaled according to the smaller of the X-axis and Y-axis scales.
If boolean is false, the element's symbols are drawn at the designated
size, regardless of axis scales. The default is 0 .
- -smooth smooth
- Specifies
how connecting line segments are drawn between data points. Smooth can
be either linear , step , natural , or quadratic . If smooth is linear
, a single line segment is drawn, connecting both data points. When smooth
is step , two line segments are drawn. The first is a horizontal line
segment that steps the next X-coordinate. The second is a vertical line,
moving to the next Y-coordinate. Both natural and quadratic generate
multiple segments between data points. If natural , the segments are generated
using a cubic spline. If quadratic , a quadratic spline is used. The default
is linear .
- -styles styleList
- Specifies what pen to use based on the
range of weights given. StyleList is a list of style specifications. Each
style specification, in turn, is a list consisting of a pen name, and
optionally a minimum and maximum range. Data points whose weight (see
the -weight option) falls in this range, are drawn with this pen. If no
range is specified it defaults to the index of the pen in the list. Note
that this affects only symbol attributes. Line attributes, such as line
width, dashes, etc. are ignored.
- -symbol symbol
- Specifies the symbol for
data points. Symbol can be either square , circle , diamond , plus ,
cross , splus , scross , triangle , "" (where no symbol is drawn), or
a bitmap. Bitmaps are specified as "source ?mask ?", where source is
the name of the bitmap, and mask is the bitmap's optional mask. The default
is circle .
- -trace direction
- Indicates whether connecting lines between
data points (whose X-coordinate values are either increasing or decreasing)
are drawn. Direction must be increasing , decreasing , or both . For
example, if direction is increasing , connecting lines will be drawn
only between those data points where X-coordinate values are monotonically
increasing. If direction is both , connecting lines will be draw between
all data points. The default is both .
- -weights wVec
- Specifies the weights
of the individual data points. This, with the list pen styles (see the
-styles option), controls how data points are drawn. WVec is the name
of a BLT vector or a list of numeric expressions representing the weights
for each data point.
- -xdata xVec
- Specifies the X-coordinates of the data.
XVec is the name of a BLT vector or a list of numeric expressions.
- -ydata
yVec
- Specifies the Y-coordinates of the data. YVec is the name of a
BLT vector or a list of numeric expressions.
Element configuration options
may also be set by the option command. The resource class is Element
. The resource name is the name of the element.
option add *Graph.Element.symbol
line
option add *Graph.e1.symbol line
- pathName element create elemName
?option value ?...
- Creates a new element elemName . It's an error is an
element elemName already exists. If additional arguments are present,
they specify options valid for the element configure operation.
- pathName
element deactivate elemName ?elemName ?...
- Deactivates all the elements
matching pattern . Elements whose names match any of the patterns given
are redrawn using their normal colors.
- pathName element delete ?elemName
?...
- Deletes all the named elements. The graph is automatically redrawn.
- pathName element exists elemName
- Returns 1 if an element elemName
currently exists and 0 otherwise.
- pathName element names ?pattern ?...
- Returns the elements matching one or more pattern. If no pattern is
given, the names of all elements is returned.
- pathName element show ?nameList
?
- Queries or modifies the element display list. The element display
list designates the elements drawn and in what order. NameList is a list
of elements to be displayed in the order they are named. If there is no
nameList argument, the current display list is returned.
- pathName element
type elemName
- Returns the type of elemName . If the element is a bar
element, the commands returns the string "bar" , otherwise it returns
"line" .
Grid lines extend from the major and minor ticks
of each axis horizontally or vertically across the plotting area. The
following operations are available for grid lines.
- pathName grid cget option
- Returns the current value of the grid line configuration option given
by option . Option may be any option described below for the grid configure
operation.
- pathName grid configure ?option value ?...
- Queries or modifies
the configuration options for grid lines. If option isn't specified, a
list describing all the current grid options for pathName is returned.
If option is specified, but not value , then a list describing option
is returned. If one or more option and value pairs are specified, then
for each pair, the grid line option option is set to value . The following
options are valid for grid lines.
- -color color
- Sets the color of the
grid lines. The default is black .
- -dashes dashList
- Sets the dash style
of the grid lines. DashList is a list of up to 11 numbers that alternately
represent the lengths of the dashes and gaps on the grid lines. Each number
must be between 1 and 255. If dashList is "" , the grid will be solid
lines.
- -hide boolean
- Indicates whether the grid should be drawn. If boolean
is true, grid lines are not shown. The default is yes .
- -linewidth pixels
- Sets the width of grid lines. The default width is 1 .
- -mapx xAxis
- Specifies
the X-axis to display grid lines. XAxis must be the name of an axis or
"" for no grid lines. The default is "" .
- -mapy yAxis
- Specifies the
Y-axis to display grid lines. YAxis must be the name of an axis or ""
for no grid lines. The default is y .
- -minor boolean
- Indicates whether
the grid lines should be drawn for minor ticks. If boolean is true, the
lines will appear at minor tick intervals. The default is 1 .
Grid configuration
options may also be set by the option command. The resource name and
class are grid and Grid respectively.
option add *Graph.grid.LineWidth
2
option add *Graph.Grid.Color black
- pathName grid off
- Turns off
the display the grid lines.
- pathName grid on
- Turns on the display the
grid lines.
- pathName grid toggle
- Toggles the display of the grid.
The legend displays a list of the data elements. Each entry
consists of the element's symbol and label. The legend can appear in any
margin (the default location is in the right margin). It can also be positioned
anywhere within the plotting area.
The following operations are valid for
the legend.
- pathName legend activate pattern ...
- Selects legend entries to
be drawn using the active legend colors and relief. All entries whose element
names match pattern are selected. To be selected, the element name must
match only one pattern .
- pathName legend bind tagName ?sequence ? ?command
?
- Associates command with tagName such that whenever the event sequence
given by sequence occurs for a legend entry with this tag, command will
be invoked. Implicitly the element names in the entry are tags. The syntax
is similar to the bind command except that it operates on legend entries,
rather than widgets. See the bind manual entry for complete details on
sequence and the substitutions performed on command before invoking
it.
If all arguments are specified then a new binding is created, replacing
any existing binding for the same sequence and tagName . If the first
character of command is + then command augments an existing binding
rather than replacing it. If no command argument is provided then the
command currently associated with tagName and sequence (it's an error
occurs if there's no such binding) is returned. If both command and
sequence are missing then a list of all the event sequences for which
bindings have been defined for tagName .
- pathName legend cget option
- Returns the current value of a legend configuration option. Option may
be any option described below in the legend configure operation.
- pathName
legend configure ?option value ?...
- Queries or modifies the configuration
options for the legend. If option isn't specified, a list describing the
current legend options for pathName is returned. If option is specified,
but not value , then a list describing option is returned. If one or
more option and value pairs are specified, then for each pair, the legend
option option is set to value . The following options are valid for the
legend.
- -activebackground color
- Sets the background color for active
legend entries. All legend entries marked active (see the legend activate
operation) are drawn using this background color.
- -activeborderwidth pixels
- Sets the width of the 3-D border around the outside edge of the active
legend entries. The default is 2 .
- -activeforeground color
- Sets the foreground
color for active legend entries. All legend entries marked as active (see
the legend activate operation) are drawn using this foreground color.
- -activerelief relief
- Specifies the 3-D effect desired for active legend
entries. Relief denotes how the interior of the entry should appear relative
to the legend; for example, raised means the entry should appear to protrude
from the legend, relative to the surface of the legend. The default is
flat .
- -anchor anchor
- Tells how to position the legend relative to the
positioning point for the legend. This is dependent on the value of the
-position option. The default is center .
- left or right
- The anchor
describes how to position the legend vertically.
- top or bottom
- The
anchor describes how to position the legend horizontally.
- @x,y
- The
anchor specifies how to position the legend relative to the positioning
point. For example, if anchor is center then the legend is centered on
the point; if anchor is n then the legend will be drawn such that the
top center point of the rectangular region occupied by the legend will
be at the positioning point.
- plotarea
- The anchor specifies how to position
the legend relative to the plotting area. For example, if anchor is center
then the legend is centered in the plotting area; if anchor is ne then
the legend will be drawn such that occupies the upper right corner of
the plotting area.
- -background color
- Sets the background color of the
legend. If color is "" , the legend background with be transparent.
- -bindtags
tagList
- Specifies the binding tags for legend entries. TagList is a
list of binding tag names. The tags and their order will determine how
events are handled for legend entries. Each tag in the list matching
the current event sequence will have its Tcl command executed. The default
value is all .
- -borderwidth pixels
- Sets the width of the 3-D border around
the outside edge of the legend (if such border is being drawn; the relief
option determines this). The default is 2 pixels.
- -font fontName
- FontName
specifies a font to use when drawing the labels of each element into
the legend. The default is *-Helvetica-Bold-R-Normal-*-12-120-* .
- -foreground color
- Sets the foreground color of the text drawn for the element's label.
The default is black .
- -hide boolean
- Indicates whether the legend should
be displayed. If boolean is true, the legend will not be draw. The default
is no .
- -ipadx pad
- Sets the amount of internal padding to be added to
the width of each legend entry. Pad can be a list of one or two screen
distances. If pad has two elements, the left side of the legend entry
is padded by the first distance and the right side by the second. If pad
is just one distance, both the left and right sides are padded evenly.
The default is 2 .
- -ipady pad
- Sets an amount of internal padding to be
added to the height of each legend entry. Pad can be a list of one or
two screen distances. If pad has two elements, the top of the entry is
padded by the first distance and the bottom by the second. If pad is
just one distance, both the top and bottom of the entry are padded evenly.
The default is 2 .
- -padx pad
- Sets the padding to the left and right exteriors
of the legend. Pad can be a list of one or two screen distances. If pad
has two elements, the left side of the legend is padded by the first
distance and the right side by the second. If pad has just one distance,
both the left and right sides are padded evenly. The default is 4 .
- -pady
pad
- Sets the padding above and below the legend. Pad can be a list
of one or two screen distances. If pad has two elements, the area above
the legend is padded by the first distance and the area below by the second.
If pad is just one distance, both the top and bottom areas are padded
evenly. The default is 0 .
- -position pos
- Specifies where the legend is
drawn. The -anchor option also affects where the legend is positioned.
If pos is left , left , top , or bottom , the legend is drawn in the
specified margin. If pos is plotarea , then the legend is drawn inside
the plotting area at a particular anchor. If pos is in the form "@x,y
", where x and y are the window coordinates, the legend is drawn in
the plotting area at the specified coordinates. The default is right .
- -raised boolean
- Indicates whether the legend is above or below the data
elements. This matters only if the legend is in the plotting area. If
boolean is true, the legend will be drawn on top of any elements that
may overlap it. The default is no .
- -relief relief
- Specifies the 3-D effect
for the border around the legend. Relief specifies how the interior of
the legend should appear relative to the graph; for example, raised means
the legend should appear to protrude from the graph, relative to the surface
of the graph. The default is sunken .
Legend configuration options may
also be set by the option command. The resource name and class are legend
and Legend respectively.
option add *Graph.legend.Foreground blue
option
add *Graph.Legend.Relief raised
- pathName legend deactivate pattern
...
- Selects legend entries to be drawn using the normal legend colors and
relief. All entries whose element names match pattern are selected. To
be selected, the element name must match only one pattern .
- pathName legend
get pos
- Returns the name of the element whose entry is at the screen
position pos in the legend. Pos must be in the form "@x,y ", where x
and y are window coordinates. If the given coordinates do not lie over
a legend entry, "" is returned.
Pens define attributes
(both symbol and line style) for elements. Pens mirror the configuration
options of data elements that pertain to how symbols and lines are drawn.
Data elements use pens to determine how they are drawn. A data element
may use several pens at once. In this case, the pen used for a particular
data point is determined from each element's weight vector (see the element's
-weight and -style options).
One pen, called activeLine , is automatically
created. It's used as the default active pen for elements. So you can change
the active attributes for all elements by simply reconfiguring this pen.
.g pen configure "activeLine" -color green
You can create and use several
pens. To create a pen, invoke the pen component and its create operation.
.g pen create myPen
You map pens to a data element using either the
element's -pen or -activepen options.
.g element create "line1" -xdata
$x -ydata $tempData \
-pen myPen
An element can use several pens at
once. This is done by specifying the name of the pen in the element's style
list (see the -styles option).
.g element configure "line1" -styles { myPen
2.0 3.0 }
This says that any data point with a weight between 2.0 and 3.0
is to be drawn using the pen myPen . All other points are drawn with the
element's default attributes.
The following operations are available for
pen components.
- pathName pen cget penName option
- Returns the current
value of the option given by option for penName . Option may be any
option described below for the pen configure operation.
- pathName pen configure
penName ?penName ... ?option value ?...
- Queries or modifies the configuration
options of penName . Several pens can be modified at once. If option isn't
specified, a list describing the current options for penName is returned.
If option is specified, but not value , then a list describing option
is returned. If one or more option and value pairs are specified, then
for each pair, the pen option option is set to value . The following
options are valid for pens.
- -color color
- Sets the color of the traces
connecting the data points.
- -dashes dashList
- Sets the dash style of
element line. DashList is a list of up to 11 numbers that alternately
represent the lengths of the dashes and gaps on the element line. Each
number must be between 1 and 255. If dashList is "" , the lines will
be solid.
- -fill color
- Sets the interior color of symbols. If color is
"" , then the interior of the symbol is transparent. If color is defcolor
, then the color will be the same as the -color option. The default is
defcolor .
- -linewidth pixels
- Sets the width of the connecting lines between
data points. If pixels is 0 , no connecting lines will be drawn between
symbols. The default is 0 .
- -offdash color
- Sets the color of the stripes
when traces are dashed (see the -dashes option). If color is "" , then
the "off" pixels will represent gaps instead of stripes. If color is
defcolor , then the color will be the same as the -color option. The default
is defcolor .
- -outline color
- Sets the color or the outline around each
symbol. If color is "" , then no outline is drawn. If color is defcolor
, then the color will be the same as the -color option. The default is
defcolor .
- -outlinewidth pixels
- Sets the width of the outline bordering
each symbol. If pixels is 0 , no outline will be drawn. The default is
1 .
- -pixels pixels
- Sets the size of symbols. If pixels is 0 , no symbols
will be drawn. The default is 0.125i .
- -symbol symbol
- Specifies the symbol
for data points. Symbol can be either square , circle , diamond , plus
, cross , splus , scross , triangle , "" (where no symbol is drawn),
or a bitmap. Bitmaps are specified as "source ?mask ?", where source
is the name of the bitmap, and mask is the bitmap's optional mask. The
default is circle .
- -type elemType
- Specifies the type of element the
pen is to be used with. This option should only be employed when creating
the pen. This is for those that wish to mix different types of elements
(bars and lines) on the same graph. The default type is "line".
Pen configuration
options may be also be set by the option command. The resource class
is Pen . The resource names are the names of the pens.
option add *Graph.Pen.Color
blue
option add *Graph.activeLine.color green
- pathName pen create penName
?option value ?...
- Creates a new pen by the name penName . No pen by the
same name can already exist. Option and value are described in above
in the pen configure operation.
- pathName pen delete ?penName ?...
- Deletes
the named pens. A pen is not really deleted until it is not longer in use,
so it's safe to delete pens mapped to elements.
- pathName pen names ?pattern
?...
- Returns a list of pens matching zero or more patterns. If no pattern
argument is give, the names of all pens are returned.
The graph can generate encapsulated PostScript output. There are several
configuration options you can specify to control how the plot will be
generated. You can change the page dimensions and borders. The plot itself
can be scaled, centered, or rotated to landscape. The PostScript output
can be written directly to a file or returned through the interpreter.
The following postscript operations are available.
- pathName postscript
cget option
- Returns the current value of the postscript option given
by option . Option may be any option described below for the postscript
configure operation.
- pathName postscript configure ?option value ?...
- Queries
or modifies the configuration options for PostScript generation. If option
isn't specified, a list describing the current postscript options for
pathName is returned. If option is specified, but not value , then a
list describing option is returned. If one or more option and value
pairs are specified, then for each pair, the postscript option option
is set to value . The following postscript options are available.
- -center
boolean
- Indicates whether the plot should be centered on the PostScript
page. If boolean is false, the plot will be placed in the upper left
corner of the page. The default is 1 .
- -colormap varName
- VarName must
be the name of a global array variable that specifies a color mapping
from the X color name to PostScript. Each element of varName must consist
of PostScript code to set a particular color value (e.g. ``1.0 1.0 0.0 setrgbcolor
''). When generating color information in PostScript, the array variable
varName is checked if an element of the name as the color exists. If so,
it uses its value as the PostScript command to set the color. If this
option hasn't been specified, or if there isn't an entry in varName for
a given color, then it uses the red, green, and blue intensities from
the X color.
- -colormode mode
- Specifies how to output color information.
Mode must be either color (for full color output), gray (convert all
colors to their gray-scale equivalents) or mono (convert foreground colors
to black and background colors to white). The default mode is color .
- -fontmap varName
- VarName must be the name of a global array variable
that specifies a font mapping from the X font name to PostScript. Each
element of varName must consist of a Tcl list with one or two elements;
the name and point size of a PostScript font. When outputting PostScript
commands for a particular font, the array variable varName is checked
to see if an element by the specified font exists. If there is such an
element, then the font information contained in that element is used in
the PostScript output. (If the point size is omitted from the list, the
point size of the X font is used). Otherwise the X font is examined in
an attempt to guess what PostScript font to use. This works only for fonts
whose foundry property is Adobe (such as Times, Helvetica, Courier, etc.).
If all of this fails then the font defaults to Helvetica-Bold .
- -decorations
boolean
- Indicates whether PostScript commands to generate color backgrounds
and 3-D borders will be output. If boolean is false, the background will
be white and no 3-D borders will be generated. The default is 1 .
- -height
pixels
- Sets the height of the plot. This lets you print the graph with
a height different from the one drawn on the screen. If pixels is 0,
the height is the same as the widget's height. The default is 0 .
- -landscape
boolean
- If boolean is true, this specifies the printed area is to be
rotated 90 degrees. In non-rotated output the X-axis of the printed area
runs along the short dimension of the page (``portrait'' orientation); in
rotated output the X-axis runs along the long dimension of the page (``landscape''
orientation). Defaults to 0 .
- -maxpect boolean
- Indicates to scale the
plot so that it fills the PostScript page. The aspect ratio of the graph
is still retained. The default is 0 .
- -padx pad
- Sets the horizontal padding
for the left and right page borders. The borders are exterior to the plot.
Pad can be a list of one or two screen distances. If pad has two elements,
the left border is padded by the first distance and the right border by
the second. If pad has just one distance, both the left and right borders
are padded evenly. The default is 1i .
- -pady pad
- Sets the vertical padding
for the top and bottom page borders. The borders are exterior to the plot.
Pad can be a list of one or two screen distances. If pad has two elements,
the top border is padded by the first distance and the bottom border by
the second. If pad has just one distance, both the top and bottom borders
are padded evenly. The default is 1i .
- -paperheight pixels
- Sets the height
of the postscript page. This can be used to select between different page
sizes (letter, A4, etc). The default height is 11.0i .
- -paperwidth pixels
- Sets the width of the postscript page. This can be used to select between
different page sizes (letter, A4, etc). The default width is 8.5i .
- -width
pixels
- Sets the width of the plot. This lets you generate a plot of
a width different from that of the widget. If pixels is 0, the width
is the same as the widget's width. The default is 0 .
Postscript configuration
options may be also be set by the option command. The resource name and
class are postscript and Postscript respectively.
option add *Graph.postscript.Decorations
false
option add *Graph.Postscript.Landscape true
- pathName postscript
output ?fileName ? ?option value ?...
- Outputs a file of encapsulated PostScript.
If a fileName argument isn't present, the command returns the PostScript.
If any option-value pairs are present, they set configuration options
controlling how the PostScript is generated. Option and value can be
anything accepted by the postscript configure operation above.
Markers are simple drawing procedures used to annotate or highlight
areas of the graph. Markers have various types: text strings, bitmaps,
images, connected lines, windows, or polygons. They can be associated
with a particular element, so that when the element is hidden or un-hidden,
so is the marker. By default, markers are the last items drawn, so that
data elements will appear in behind them. You can change this by configuring
the -under option.
Markers, in contrast to elements, don't affect the scaling
of the coordinate axes. They can also have elastic coordinates (specified
by -Inf and Inf respectively) that translate into the minimum or maximum
limit of the axis. For example, you can place a marker so it always remains
in the lower left corner of the plotting area, by using the coordinates
-Inf ,-Inf .
The following operations are available for markers.
- pathName
marker after markerId ?afterId ?
- Changes the order of the markers, drawing
the first marker after the second. If no second afterId argument is specified,
the marker is placed at the end of the display list. This command can
be used to control how markers are displayed since markers are drawn in
the order of this display list.
- pathName marker before markerId ?beforeId
?
- Changes the order of the markers, drawing the first marker before the
second. If no second beforeId argument is specified, the marker is placed
at the beginning of the display list. This command can be used to control
how markers are displayed since markers are drawn in the order of this
display list.
- pathName marker bind tagName ?sequence ? ?command ?
- Associates
command with tagName such that whenever the event sequence given by
sequence occurs for a marker with this tag, command will be invoked.
The syntax is similar to the bind command except that it operates on
graph markers, rather than widgets. See the bind manual entry for complete
details on sequence and the substitutions performed on command before
invoking it.
If all arguments are specified then a new binding is created,
replacing any existing binding for the same sequence and tagName . If
the first character of command is + then command augments an existing
binding rather than replacing it. If no command argument is provided
then the command currently associated with tagName and sequence (it's
an error occurs if there's no such binding) is returned. If both command
and sequence are missing then a list of all the event sequences for
which bindings have been defined for tagName .
- pathName marker cget option
- Returns the current value of the marker configuration option given by
option . Option may be any option described below in the configure operation.
- pathName marker configure markerId ?option value ?...
- Queries or modifies
the configuration options for markers. If option isn't specified, a list
describing the current options for markerId is returned. If option is
specified, but not value , then a list describing option is returned.
If one or more option and value pairs are specified, then for each pair,
the marker option option is set to value .
The following options are
valid for all markers. Each type of marker also has its own type-specific
options. They are described in the sections below.
- -bindtags tagList
- Specifies the binding tags for the marker. TagList is a list of binding
tag names. The tags and their order will determine how events for markers
are handled. Each tag in the list matching the current event sequence
will have its Tcl command executed. Implicitly the name of the marker
is always the first tag in the list. The default value is all .
- -coords coordList
- Specifies the coordinates of the marker. CoordList is a list of graph
coordinates. The number of coordinates required is dependent on the type
of marker. Text, image, and window markers need only two coordinates (an
X-Y coordinate). Bitmap markers can take either two or four coordinates
(if four, they represent the corners of the bitmap). Line markers need
at least four coordinates, polygons at least six. If coordList is "" ,
the marker will not be displayed. The default is "" .
- -element elemName
- Links the marker with the element elemName . The marker is drawn only
if the element is also currently displayed (see the element's show operation).
If elemName is "" , the marker is always drawn. The default is "" .
- -hide
boolean
- Indicates whether the marker is drawn. If boolean is true,
the marker is not drawn. The default is no .
- -mapx xAxis
- Specifies the
X-axis to map the marker's X-coordinates onto. XAxis must the name of an
axis. The default is x .
- -mapy yAxis
- Specifies the Y-axis to map the marker's
Y-coordinates onto. YAxis must the name of an axis. The default is y .
- -name
markerId
- Changes the identifier for the marker. The identifier markerId
can not already be used by another marker. If this option isn't specified,
the marker's name is uniquely generated.
- -under boolean
- Indicates whether
the marker is drawn below/above data elements. If boolean is true, the
marker is be drawn underneath the data element symbols and lines. Otherwise,
the marker is drawn on top of the element. The default is 0 .
- -xoffset pixels
- Specifies a screen distance to offset the marker horizontally. Pixels
is a valid screen distance, such as 2 or 1.2i . The default is 0 .
- -yoffset
pixels
- Specifies a screen distance to offset the markers vertically.
Pixels is a valid screen distance, such as 2 or 1.2i . The default is
0 .
Marker configuration options may also be set by the option command.
The resource class is either BitmapMarker , ImageMarker , LineMarker
, PolygonMarker , TextMarker , or WindowMarker , depending on the type
of marker. The resource name is the name of the marker.
option add *Graph.TextMarker.Foreground
white
option add *Graph.BitmapMarker.Foreground white
option add *Graph.m1.Background
blue
- pathName marker create type ?option value ?...
- Creates a marker
of the selected type. Type may be either text , line , bitmap , image
, polygon , or window . This command returns the marker identifier, used
as the markerId argument in the other marker-related commands. If the
-name option is used, this overrides the normal marker identifier. If
the name provided is already used for another marker, the new marker will
replace the old.
- pathName marker delete ?name ?...
- Removes one of more markers.
The graph will automatically be redrawn without the marker. .
- pathName
marker exists markerId
- Returns 1 if the marker markerId exists and
0 otherwise.
- pathName marker names ?pattern ?
- Returns the names of
all the markers that currently exist. If pattern is supplied, only those
markers whose names match it will be returned.
- pathName marker type markerId
- Returns the type of the marker given by markerId , such as line or
text . If markerId is not a valid a marker identifier, "" is returned.
A bitmap marker displays a bitmap. The size of the bitmap
is controlled by the number of coordinates specified. If two coordinates,
they specify the position of the top-left corner of the bitmap. The bitmap
retains its normal width and height. If four coordinates, the first and
second pairs of coordinates represent the corners of the bitmap. The bitmap
will be stretched or reduced as necessary to fit into the bounding rectangle.
Bitmap markers are created with the marker's create operation in the form:
pathName marker create bitmap ?option value ?...
There may be many option
-value pairs, each sets a configuration options for the marker. These
same option -value pairs may be used with the marker's configure operation.
The following options are specific to bitmap markers:
- -background color
- Same as the -fill option.
- -bitmap bitmap
- Specifies the bitmap to be
displayed. If bitmap is "" , the marker will not be displayed. The default
is "" .
- -fill color
- Sets the background color of the bitmap. If color
is the empty string, no background will be transparent. The default background
color is "" .
- -foreground color
- Same as the -outline option.
- -mask mask
- Specifies a mask for the bitmap to be displayed. This mask is a bitmap
itself, denoting the pixels that are transparent. If mask is "" , all
pixels of the bitmap will be drawn. The default is "" .
- -outline color
- Sets the foreground color of the bitmap. The default value is black .
- -rotate
theta
- Sets the rotation of the bitmap. Theta is a real number representing
the angle of rotation in degrees. The marker is first rotated and then
placed according to its anchor position. The default rotation is 0.0 .
A image marker displays an image. Image markers are created
with the marker's create operation in the form:
pathName marker create
image ?option value ?...
There may be many option -value pairs, each sets
a configuration option for the marker. These same option -value pairs
may be used with the marker's configure operation.
The following options
are specific to image markers:
- -anchor anchor
- Anchor tells how to position
the image relative to the positioning point for the image. For example,
if anchor is center then the image is centered on the point; if anchor
is n then the image will be drawn such that the top center point of
the rectangular region occupied by the image will be at the positioning
point. This option defaults to center .
- -image image
- Specifies the image
to be drawn. If image is "" , the marker will not be drawn. The default
is "" .
A line marker displays one or more connected line
segments. Line markers are created with marker's create operation in the
form:
pathName marker create line ?option value ?...
There may be many
option -value pairs, each sets a configuration option for the marker.
These same option -value pairs may be used with the marker's configure
operation.
The following options are specific to line markers:
- -dashes
dashList
- Sets the dash style of the line. DashList is a list of up to
11 numbers that alternately represent the lengths of the dashes and gaps
on the line. Each number must be between 1 and 255. If dashList is ""
, the marker line will be solid.
- -fill color
- Sets the background color
of the line. This color is used with striped lines (see the -fdashes option).
If color is the empty string, no background color is drawn (the line
will be dashed, not striped). The default background color is "" .
- -linewidth
pixels
- Sets the width of the lines. The default width is 0 .
- -outline color
- Sets the foreground color of the line. The default value is black .
- -stipple
bitmap
- Specifies a stipple pattern used to draw the line, rather than
a solid line. Bitmap specifies a bitmap to use as the stipple pattern.
If bitmap is "" , then the line is drawn in a solid fashion. The default
is "" .
A polygon marker displays a closed region described
as two or more connected line segments. It is assumed the first and last
points are connected. Polygon markers are created using the marker create
operation in the form:
pathName marker create polygon ?option value
?...
There may be many option -value pairs, each sets a configuration option
for the marker. These same option -value pairs may be used with the marker
configure command to change the marker's configuration. The following options
are supported for polygon markers:
- -dashes dashList
- Sets the dash style
of the outline of the polygon. DashList is a list of up to 11 numbers
that alternately represent the lengths of the dashes and gaps on the outline.
Each number must be between 1 and 255. If dashList is "" , the outline
will be a solid line.
- -fill color
- Sets the fill color of the polygon.
If color is "" , then the interior of the polygon is transparent. The
default is white .
- -linewidth pixels
- Sets the width of the outline of
the polygon. If pixels is zero, no outline is drawn. The default is 0
.
- -outline color
- Sets the color of the outline of the polygon. If the
polygon is stippled (see the -stipple option), then this represents the
foreground color of the stipple. The default is black .
- -stipple bitmap
- Specifies that the polygon should be drawn with a stippled pattern rather
than a solid color. Bitmap specifies a bitmap to use as the stipple pattern.
If bitmap is "" , then the polygon is filled with a solid color (if
the -fill option is set). The default is "" .
A text marker
displays a string of characters on one or more lines of text. Embedded
newlines cause line breaks. They may be used to annotate regions of the
graph. Text markers are created with the create operation in the form:
pathName marker create text ?option value ?...
There may be many option
-value pairs, each sets a configuration option for the text marker.
These same option -value pairs may be used with the marker's configure
operation.
The following options are specific to text markers:
- -anchor
anchor
- Anchor tells how to position the text relative to the positioning
point for the text. For example, if anchor is center then the text is
centered on the point; if anchor is n then the text will be drawn such
that the top center point of the rectangular region occupied by the text
will be at the positioning point. This default is center .
- -background color
- Same as the -fill option.
- -font fontName
- Specifies the font of the text.
The default is *-Helvetica-Bold-R-Normal-*-120-* .
- -fill color
- Sets the background
color of the text. If color is the empty string, no background will be
transparent. The default background color is "" .
- -foreground color
- Same
as the -outline option.
- -justify justify
- Specifies how the text should
be justified. This matters only when the marker contains more than one
line of text. Justify must be left , right , or center . The default is
center .
- -outline color
- Sets the color of the text. The default value is
black .
- -padx pad
- Sets the padding to the left and right exteriors of
the text. Pad can be a list of one or two screen distances. If pad has
two elements, the left side of the text is padded by the first distance
and the right side by the second. If pad has just one distance, both
the left and right sides are padded evenly. The default is 4 .
- -pady pad
- Sets the padding above and below the text. Pad can be a list of one
or two screen distances. If pad has two elements, the area above the
text is padded by the first distance and the area below by the second.
If pad is just one distance, both the top and bottom areas are padded
evenly. The default is 4 .
- -rotate theta
- Specifies the number of degrees
to rotate the text. Theta is a real number representing the angle of
rotation. The marker is first rotated along its center and is then drawn
according to its anchor position. The default is 0.0 .
- -text text
- Specifies
the text of the marker. The exact way the text is displayed may be affected
by other options such as -anchor or -rotate .
A window marker
displays a widget at a given position. Window markers are created with
the marker's create operation in the form:
pathName marker create window
?option value ?...
There may be many option -value pairs, each sets a configuration
option for the marker. These same option -value pairs may be used with
the marker's configure command.
The following options are specific to window
markers:
- -anchor anchor
- Anchor tells how to position the widget relative
to the positioning point for the widget. For example, if anchor is center
then the widget is centered on the point; if anchor is n then the widget
will be displayed such that the top center point of the rectangular region
occupied by the widget will be at the positioning point. This option defaults
to center .
- -height pixels
- Specifies the height to assign to the marker's
window. If this option isn't specified, or if it is specified as "" , then
the window is given whatever height the widget requests internally.
- -width
pixels
- Specifies the width to assign to the marker's window. If this
option isn't specified, or if it is specified as "" , then the window is
given whatever width the widget requests internally.
- -window pathName
- Specifies the widget to be managed by the graph. PathName must be a child
of the graph widget.
Specific graph components,
such as elements, markers and legend entries, can have a command trigger
when event occurs in them, much like canvas items in Tk's canvas widget.
Not all event sequences are valid. The only binding events that may be
specified are those related to the mouse and keyboard (such as Enter ,
Leave , ButtonPress , Motion , and KeyPress ).
Only one element or marker
can be picked during an event. This means, that if the mouse is directly
over both an element and a marker, only the uppermost component is selected.
This isn't true for legend entries. Both a legend entry and an element
(or marker) binding commands will be invoked if both items are picked.
It is possible for multiple bindings to match a particular event. This
could occur, for example, if one binding is associated with the element
name and another is associated with one of the element's tags (see the
-bindtags option). When this occurs, all of the matching bindings are
invoked. A binding associated with the element name is invoked first,
followed by one binding for each of the element's bindtags. If there are
multiple matching bindings for a single tag, then only the most specific
binding is invoked. A continue command in a binding script terminates
that script, and a break command terminates that script and skips any
remaining scripts for the event, just as for the bind command.
The -bindtags
option for these components controls addition tag names which can be
matched. Implicitly elements and markers always have tags matching their
names. Setting the value of the -bindtags option doesn't change this.
You can manipulate data elements from the C language. There
may be situations where it is too expensive to translate the data values
from ASCII strings. Or you might want to read data in a special file format.
Data can manipulated from the C language using BLT vectors. You specify
the X-Y data coordinates of an element as vectors and manipulate the vector
from C. The graph will be redrawn automatically after the vectors are
updated.
From Tcl, create the vectors and configure the element to use
them.
vector X Y
.g element configure line1 -xdata X -ydata Y
To set data
points from C, you pass the values as arrays of doubles using the Blt_ResetVector
call. The vector is reset with the new data and at the next idle point
(when Tk re-enters its event loop), the graph will be redrawn automatically.
#include <tcl.h>
#include <blt.h>
register int i;
Blt_Vector *xVec,
*yVec;
double x[50], y[50];
/* Get the BLT vectors "X" and "Y" (created
above from Tcl) */
if ((Blt_GetVector(interp, "X", &xVec) != TCL_OK) ||
(Blt_GetVector(interp, "Y", &yVec) != TCL_OK)) {
return TCL_ERROR;
}
for (i = 0; i < 50; i++) {
x[i] = i * 0.02;
y[i] = sin(x[i]);
}
/* Put the data into BLT vectors */
if ((Blt_ResetVector(xVec,
x, 50, 50, TCL_VOLATILE) != TCL_OK) ||
(Blt_ResetVector(yVec, y, 50,
50, TCL_VOLATILE) != TCL_OK)) {
return TCL_ERROR;
}
See the vector
manual page for more details.
There may be cases where the
graph needs to be drawn and updated as quickly as possible. If drawing
speed becomes a big problem, here are a few tips to speed up displays.
·- Try to minimize the number of data points. The more data points the looked
at, the more work the graph must do.
·- If your data is generated as floating
point values, the time required to convert the data values to and from
ASCII strings can be significant, especially when there any many data
points. You can avoid the redundant string-to-decimal conversions using
the C API to BLT vectors.
·- Data elements without symbols are drawn faster
than with symbols. Set the data element's -symbol option to none . If you
need to draw symbols, try using the simple symbols such as splus and
scross .
·- Don't stipple or dash the element. Solid lines are much faster.
·- If you update data elements frequently, try turning off the widget's -bufferelements
option. When the graph is first displayed, it draws data elements into
an internal pixmap. The pixmap acts as a cache, so that when the graph
needs to be redrawn again, and the data elements or coordinate axes haven't
changed, the pixmap is simply copied to the screen. This is especially
useful when you are using markers to highlight points and regions on the
graph. But if the graph is updated frequently, changing either the element
data or coordinate axes, the buffering becomes redundant.
Auto-scale routines do not use requested min/max limits as boundaries when
the axis is logarithmically scaled.
The PostScript output generated for
polygons with more than 1500 points may exceed the limits of some printers
(See PostScript Language Reference Manual, page 568). The work-around is
to break the polygon into separate pieces.
graph, widget
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