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Xprism2 is a 2D plotting package for use independently or with other
parts of Khoros.
It features 2D, Discrete, Bar Graph, Polymarker and Linemarker plots.
There are many ways to input data -- image files, files with functions
or data points, and functions entered from the keyboard.  The data format
may be represented as XY pairs or as Y data only.  For raw data files, the
standard data types of Byte, Short, Integer, or Float may be selected.
In addition, the machine type may be selected to indicate the data
ordering from the machine on which the data was created.  This allows the
user to make use of raw data files created on a variety of other machines.
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Displayed plots can be scaled, rotated, and translated. Fonts, colors, axes,
marker types, line types, plot types, and titles can be changed. 
Plot information can be saved implicitly or explicitly in Image File Format. 
Output may be sent to Postscript, Imagen, or LNO3 laser printers, or to
an HPGL plotter.  
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The user interface is broken down into a "master" form and five "subforms".
Each "subform" represents a group of operations that may be accessed by 
selecting the desired "subform" button.  
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Subforms
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.IP Plot 15
Used to create and display plots.
.IP Options 15
Used to customize a plot.
.IP Annotations 15
Used to annotatate a plot.
.IP Output 15
Used to send a plot to a printer or save it as a VIFF file.
.IP "Answer Files" 15
Used to read and write xprism2 answer files.
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In addition, each "subform" 
contains a number of "panes" that allow the user to enter information
appropriate to desired plot.
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There are also seven "action" buttons located on the left side of the
"master" form, which allow the user to obtain information about the plot 
and to perform certain operations on the workspace. 
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Action Buttons
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.IP "PLOT INFO" 15
Used to get statistics about a plot.
.IP REFRESH 15
Used to redraw the workspace.
.IP CLEAR 15
Used to completely clear the workspace.
.IP HIDE 15
Used to hide one or more plots.
.IP DELETE 15
Used to delete one or more plots.
.IP RESET AXES 15
Used to reset the axes to a certain plot
.IP HELP 15
Displays this documentation.
.IP QUIT 15
Exit from Xprism2.
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For more detailed information on each of these operation, see the HELP
that is pertinent to the operation that is desired.
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USE WITH KHOROS
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Among other uses of the plotting routines, you can get a graphical
representation of an image by plotting the image file with xprism2.  
Image files can be represented as 2D or 3D graphs.  
In 2D, each row of the image is interpreted as lying on the X axis, so that 
rows are set sequentially end to end, and the grey level of each pixel is 
interpreted as the y value at that point.
In addition, plots created can be saved as image files, and later used
with editimage. 
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RESTRICTIONS
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Xprism2 has a few minor problems. The following list describes the
known problems with xprism2:
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The function parser may not trap arithmetic errors such as overflows, 
underflows and divide by zero. These arithmetic errors will cause Xprism
to core dump.
.IP 2
If you are using annotations, it may be necessary to redraw the
plot periodically. After moving, rasing or lowering and annotation
it is best to press the "REFRESH" button on the left side of the
xprism mast form.
.IP 3
The output of annotations to an impress printer does not work. It is
best to avoid annotating a plot if your output device is an impress
printer. 
