stripchart - 2D strip chart for plotting x and y coordinate
data.
stripchart pathName ?option
value?...
The stripchart command creates a strip chart 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 strip chart.
The stripchart is essentially the same as the graph
widget. It works almost exactly the very same way.
The use of a strip chart differs in that the X-axis typically
refers to time points. Data values are added at intervals. The strip chart
lets you automatically maintain a view of the most recent time points. The
axis options -shiftby and -autorange control this. You can
specify different line styles for data points (see the -styles
option).
The stripchart command creates a new window for plotting
two-dimensional data (x,y coordinates). Data points are plotted in a box
displayed in the center of the new window. This is the plotting area.
The coordinate axes are displayed in the margins around the plotting area.
By default, the legend is displayed in the right margin. The title is
displayed in top margin.
A strip chart is composed of several components: coordinate axes,
data elements, legend, grid, cross hairs, pens, postscript, and annotation
markers.
- axis
- The stripchart widget can display up to four coordinate axes (two
X-coordinate and two Y-coordinate axes), but you can create and use 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 of each major
tick.
- crosshairs
- Cross hairs are used to finely position the mouse pointer in relation to
the coordinate axes. Two perpendicular lines are drawn across the plotting
area, intersecting at the current location of the mouse pointer.
- 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.
stripchart pathName ?option value?...
The stripchart command creates a new window pathName
and makes it into a stripchart 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 may be specified
on the command line or in the option database to configure aspects of the
strip chart such as its colors and font. See the configure operation
below for the exact details as to what option and value pairs
are valid.
If successful, stripchart returns the path name of the
widget. It also creates a new Tcl command by the same name. You can use this
command to perform 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 strip chart are
described in the STRIPCHART OPERATIONS section.
The command can also be used to access components of the strip
chart.
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 stripchart command creates a new strip chart.
# Create a new strip chart. Plotting area is black.
stripchart .s -plotbackground black
A new Tcl command .s is also created. This command can be
used to query and modify the strip chart. For example, to change the title
of the strip chart to "My Plot", you use the new command and the
widget's configure operation.
# Change the title.
.s configure -title "My Plot"
A strip chart 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"
.s 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 and 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 strip chart.
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 }
.s element create line1 -xdata xVec -ydata yVec
The advantage of using vectors is that when you modify one, the
graph is automatically redrawn to display the new values.
# 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 .s. 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.
.s 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.
.s 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".
.s 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
operation.
# Y-axis is log scale.
.s axis configure y -logscale yes
Axis limits are reset by simply specifying new axis limits using
the -min and -max configuration options.
.s axis configure x -min 1.0 -max 1.5
.s axis configure y -min 12.0 -max 55.15
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.
.s axis configure x -min {} -max {}
.s axis configure y -min {} -max {}
It's common with strip charts to automatically maintain a view of
the most recent time points. You can do this my setting the
-autorange option.
.s axis configure x -autorange 20.0
If the time points are added in X-coordinates 1.0 unit, only the
last twenty time points will be displayed. As more data is added, the view
will march along.
Sometimes the rate of data is so high that changing the axis
limits with each additional time point is prohibitive. You can use the
-shiftby option to define an increment to shift the view when
needed.
.s axis configure x -shiftby 15.0
When the view is shifted, it will allow a range of 15 new time
points to be added until the axis limits are recomputed.
By default, the legend is displayed in the right margin. You can
change this or any other legend configuration options using the
legend component.
# Configure the legend font, color, and relief
.s 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.
.s legend configure -hide yes
The stripchart widget has simple drawing procedures called
markers. They can be used to highlight or annotate data in the strip chart.
The types of markers available are bitmaps, images, polygons, lines, or
windows. Markers can be used, for example, to mark or brush points. Here is
a text marker which labels the data first point. Markers are created using
the marker operation.
# Create a label for the first data point of "line1".
.s 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 actual 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.
.s marker configure first_marker -under yes
You can add cross hairs or grid lines using the crosshairs
and grid operations.
# Display both cross hairs and grid lines.
.s crosshairs configure -hide no -color red
.s grid configure -hide no -dashes { 2 2 }
Finally, to get hardcopy of the strip chart, use the
postscript operation.
# Print the strip chart into file "file.ps"
.s postscript output file.ps -maxpect yes -decorations no
This generates a file file.ps containing the encapsulated
PostScript of the strip chart. The option -maxpect says to scale the
plot to the size of the page. Turning off the -decorations option
indicates that no borders or color backgrounds should be displayed (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 stripchart 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 strip chart. If
option isn't specified, a list describing all of 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 stripchart option option is set to value. The
following options are valid for the stripchart.
- -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
- Specifies the size of the margin below the X-coordinate axis. If
pixels is 0, the size of the margin is selected
automatically. The default is 0.
- -bufferelements
boolean
- Indicates whether to draw elements into a pixmap before displaying them on
the screen. The advantage of buffering elements is when markers are used
heavily. Markers can be moved and redrawn without requiring every element
to be redrawn again. The disadvantage is that it takes slightly longer to
draw the graph. If boolean is true, data elements are drawn to an
internal pixmap. The option should be turned off if the plot is updated
frequently. See the SPEED TIPS section. The default
is 1.
- -buffergraph
boolean
- Indicates whether to draw the graph into a pixmap first. If boolean
is true, the entire graph is drawn into a pixmap and then copied onto the
screen. This reduces flashing. If false, the graph is drawn directly into
the window. Especially under Windows, turning off the option can be
helpful when the stripchart is updated frequently. Turning off this option
also turns -bufferelements off. 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 title font. 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
- Sets the size of the margin from the left edge of the window to the
Y-coordinate axis. If pixels is 0, the size is calculated
automatically. 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 indicates
how the interior of the plotting area should appear relative to rest of
the strip chart; for example, raised means the plot should appear
to protrude from the strip chart, relative to the surface of the strip
chart. The default is sunken.
- -relief
relief
- Specifies the 3-D effect for the widget. Relief indicates how the
strip chart should appear relative to widget it is packed into; for
example, raised means the strip chart should appear to protrude.
The default is flat.
- -rightmargin
pixels
- Sets the size of margin from the plotting area to the right edge of the
window. By default, the legend is displayed in this margin. If
pixels is than 1, the margin size is selected automatically.
- -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. 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
- Specifies the size of the margin above the x2 axis. If pixels is
0, the margin size is calculated automatically.
- -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 strip chart. 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 graph coordinates.
- pathName
legend operation ?arg?...
- See the LEGEND COMPONENT section.
- pathName
line elemName ?option value?...
- The operation is the same as element.
- pathName
marker operation ?arg?...
- See the MARKER COMPONENTS section.
- pathName
metafile ?fileName?
- This operation is for Window platforms only. Creates a Windows
enhanced metafile of the stripchart. If present, fileName is the
file name of the new metafile. Otherwise, the metafile is automatically
added to the clipboard.
- pathName
postscript operation ?arg?...
- See the POSTSCRIPT COMPONENT section.
- pathName
snap photoName
- Takes a snapshot of the strip chart 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 strip chart 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
strip chart is partitioned, where each component has its own configuration
options and operations that specifically control that aspect or part of the
strip chart.
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 create and use several axes. To create an axis, invoke the
axis component and its create operation.
# Create a new axis called "temperature"
.s axis create temperature
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 temperature data to this axis.
.s element create "temp" -xdata $x -ydata $tempData \
-mapy temperature
While you can have many axes, only four axes can be displayed
simultaneously. They are drawn in each of the margins surrounding the
plotting area. The axes x and y are drawn in the bottom and left margins.
The axes x2 and y2 are drawn in top and right margins. Only x and y are
shown by default. Note that the axes can have different scales.
To display a different axis, you invoke one of the following
components: xaxis, yaxis, x2axis, and y2axis.
The use operation designates the axis to be drawn in the
corresponding margin: xaxis in the bottom, yaxis in the left,
x2axis in the top, and y2axis in the right.
# Display the axis temperature in the left margin.
.s yaxis use temperature
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 as 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 ?option
value?...
- Queries or modifies the configuration options of axisName. 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 strip
chart is redrawn. You may query the configuration options. But do not
reset 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
boolean
- Indicates whether the axis is displayed.
- -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. This is relevant only when the axis limit is automatically
calculated. 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.
- -shiftby
value
- Specifies how much to automatically shift the range of the axis. When the
new data exceeds the current axis maximum, the maximum is increased in
increments of value. You can use this option to prevent the axis
limits from being recomputed at each new time point. If value is
0.0, then no automatic shifting is done. The default is 0.0.
- -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 *Stripchart.Axis.Color blue
option add *Stripchart.x.LogScale true
option add *Stripchart.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.
Only four axes can be displayed simultaneously. By default, they
are x, y, x2, and y2. You can 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. The xaxis component manages
the X-axis located in the bottom margin (whatever axis that happens to be).
Likewise, yaxis uses the Y-axis in the left margin, x2axis the
top X-axis, and y2axis the right Y-axis.
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.
These components can be more convenient to use than always determining what
axes are current being displayed by the graph.
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.
- 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 strip chart.
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 *Stripchart.Crosshairs.LineWidth 2
option add *Stripchart.Crosshairs.Color red
- pathName
crosshairs off
- Turns of 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 cget elemName option
- Returns the current value of the element configuration option given by
option. Option may be any option 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
stripchart's -halo option.
- -interpolate
boolean
- Indicates that both the data points and interpolated points along the line
segment formed should be considered. If boolean is true, the
closest line segment will be selected instead of the closest point. If
this option isn't specified, boolean defaults to 0.
- pathName
element configure elemName ?option
value?...
- Queries or modifies the configuration options for elements. 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.
- -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 which
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 upon 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 number of the pen in the list.
- -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.
- -weights
wVec
- Specifies the weights of the individual data points. This, in conjunction
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 *Stripchart.Element.symbol line
option add *Stripchart.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 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. The default is x.
- -mapy
yAxis
- Specifies the Y-axis to display grid lines. YAxis must be the name
of an axis. 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 *Stripchart.grid.LineWidth 2
option add *Stripchart.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 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.
- -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
strip chart; for example, raised means the legend should appear to
protrude from the strip chart, relative to the surface of the strip chart.
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 *Stripchart.legend.Foreground blue
option add *Stripchart.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.
.s pen configure "activeLine" -color green
You can create and use any number of pens. To create a pen, invoke
the pen component and its create operation.
You map pens to a data element using either the element's
-pen or -activepen options.
.s 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).
.s 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 ?option
value?...
- Queries or modifies the configuration options of penName. 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 *Stripchart.Pen.Color blue
option add *Stripchart.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 strip chart can generate encapsulated PostScript output. There
are several configuration options you can specify to control how the plot is
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 outputting color
information in PostScript, the array variable varName is checked to
see if an element of the name of the color exists. If so, it uses the
value of the element 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, which
are 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 an element of 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 if PostScript commands to generate color backgrounds and 3-D
borders should 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 plot the stripchart with a
height different from the one displayed on the screen. If pixels is
0, the height is the same as the displayed 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 the plot so that it fills the PostScript page. The
aspect ratio of the strip chart 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 plot the strip chart with a
width different from the one drawn on the screen. 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 *Stripchart.postscript.Decorations false
option add *Stripchart.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 strip chart. 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 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.
- -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 *Stripchart.TextMarker.Foreground white
option add *Stripchart.BitmapMarker.Foreground white
option add *Stripchart.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
- Sets the background color of the bitmap. If color is
"", the background color will be transparent. The default
background color is white.
- -bitmap
bitmap
- Specifies the bitmap to be displayed. If bitmap is
"", the marker will not be displayed. The default is
"".
- -foreground
color
- Sets the foreground color of the bitmap. The default foreground color is
black.
- -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 "".
- -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:
- -background
color
- Sets the background color of the line. The option is affects the line
color only when the -stipple option is set. If this option isn't
specified then it defaults to white.
- -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.
- -foreground
color
- Sets the foreground color. The default foreground color is
black.
- -linewidth
pixels
- Sets the width of the lines. The default width is 0.
- -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 strip chart. 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
- Sets the background color of the text string. If color is
"", the background will be transparent. The default is
white.
- -font
fontName
- Specifies the font of the text. The default is
*-Helvetica-Bold-R-Normal-*-120-*.
- -foreground
color
- Sets the foreground color of the text. The default is black.
- -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.
- -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. PathName must be a child of the
stripchart widget.
Specific stripchart 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 and y data coordinates of an element as vectors and manipulate
the vector from C. The strip chart will be redrawn automatically after the
vectors are updated.
From Tcl, create the vectors and configure the element to use
them.
vector X Y
.s 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
strip chart 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", 50, &xVec) != TCL_OK) ||
(Blt_GetVector(interp, "Y", 50, &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 strip chart 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 strip chart 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 strip chart is first displayed, it
draws data elements into an internal pixmap. The pixmap acts as a cache,
so that when the strip chart 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 strip chart. But if the strip chart 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.
The -mapped options are obsoleted and will be removed. You
can achieve the same results using the -hide option instead.
# Works for now.
.s legend configure -mapped no
# Instead use this.
.s legend configure -hide yes
stripchart, graph, widget