.TH XGRAPH 1 "December, 1989"
.SH NAME
xgraph \- Draw a graph on an X11 Display
.SH SYNOPSIS
.B xgraph
[ options ] [[-geometry |=]WxH+X+Y ] [ -display host:display.screen ] [ file ... ]
.SH DESCRIPTION
The 
.I xgraph
program draws a graph on an X display given data read from either
data files or from standard input if no files are specified.
It can display up to 64 independent data sets using different colors
and/or line styles for each set.
It annotates the graph with a title,  axis labels,  grid lines or tick
marks, grid labels,  
and a legend.
There are options to control the appearance of most components of
the graph.
.PP
The input format is similar to
.I graph(1G)
but differs slightly.
The data consists of a number of
.I "data sets."
Data sets are separated by a blank line.
A new data set is also
assumed at the start of each input file.
A data set consists of an ordered list of points of the form "{directive} X Y".
The directive is either "draw" or "move" and can be omitted.
If the directive is "draw", a line will be drawn between the previous
point and the current point (if a line graph is chosen).
Specifying a "move" directive tells xgraph not to draw a line between
the points.
If the directive is omitted, "draw" is assumed for all points in
a data set except the 
first point where "move" is assumed.
The "move" directive is used most often to allow discontinuous data
in a data set.
The name of a data set can be specified by 
enclosing the name in double quotes on a line by itself in the
body of the data set.  The trailing double quote is optional.
Overall graphing options for the graph can be specified in data
files by writing lines of the form "<option>: <value>".  The
option names are the same as those used for specifying X 
resources (see below). The option and value must be separated by at
bleast one space.
An example input file with three data sets is shown below.  Note
that set three is not named, set two has discontinuous data,
and the title of the graph is specified near the top of the file.
.sp 1
.nf
TitleText: Sample Data
0.5 7.8
1.0 6.2
"set one
1.5 8.9

"set two"
-3.4 1.4e-3
-2.0 1.9e-2
move -1.0 2.0e-2
-0.65 2.2e-4

2.2 12.8
2.4 -3.3
2.6 -32.2
2.8 -10.3
.fi
.PP
After
.I xgraph
has read the data,  it will create a new window to graphically
display the data.
The interface used to specify the size and location of this window depends
on the window manager currently in use.
Refer to the reference manual of the window manager for details.
.PP
Once the window has been opened,  all of the data sets will be displayed
graphically (subject to the options explained below) with a legend in 
the upper right corner of the screen.
To zoom in on a portion of the graph,  depress a mouse button in
the window and sweep out a region.
.I xgraph
will then open a new window looking at just that portion of the graph.
.I xgraph
also presents three control buttons in the upper left corner of
each window:
.I Close,
.I Hardcopy,
and
.I About.
Windows are closed by depressing a mouse button while the mouse
cursor is inside the
.I Close
button.  Typing EOF (control-D) in a window also closes that window.
Depressing a mouse button while the mouse cursor is in the
.I Hardcopy
button causes a dialog to appear asking about hardcopy (printout)
options.  These options are described below:
.IP "Output Device"
Specifies the type of the output device (e.g. "HPGL", "Postscript", etc).
An output device is chosen by depressing the mouse inside its name.
The default values of other fields will change when you select a
different output device.
.IP "Disposition"
Specifies whether the output should go directly to a device
or to a file.  Again,  the default values of other fields will change
when you select a different disposition.
.IP "File or Device Name"
If the disposition is "To Device",  this field specifies the device
name.
A device name is the same as the name given for the -P command
of lpr(1).
If the disposition is "To File",  this field specifies the name
of the output file.
.IP "Maximum Dimension"
This specifies the maximum size of the plot on the hardcopy
device in centimeters.
.I xgraph
takes in account the aspect ratio of the plot on the screen
and will scale the plot so that the longer side of the plot
is no more than the value of this parameter.
If the device supports it,  the plot may also be rotated on the page
based on the value of the maximum dimension.
.IP "Include in Document"
If selected, this option causes
.I xgraph
to produce harcopy output that is suitable for inclusion in other
larger documents.
As an example,  when this option is selected the Postscript output 
produced by xgraph will have a bounding box suitable for use with
psfig.
.IP "Title Font Family"
This field specifies the name of a font to use when drawing
the graph title.  Suitable defaults are initially chosen for
any given hardcopy device.
The value of this field is hardware specific -- refer to
the device reference manual for details.
.IP "Title Font Size"
This field specifies the desired size of the title fonts in points
(1/72 of an inch).  
If the device supports scalable fonts,  the
font will be scaled to this size.
.IP "Axis Font Family and Axis Font Size"
These fields are like
.I "Title Font Family"
and
.I "Title Font Size"
except they specify values for the font
.I xgraph
uses to draw axis labels, and legend descriptions.
.IP "Control Buttons"
After specifing the parameters for the plot,  the "Ok" button causes
.I xgraph
to produce a hardcopy.
Pressing the "Cancel" button will abort the hardcopy operation.
Depressing the
.I About
button causes Xgraph to display a window containing the version of
the program and an electronic mailing address for the author
for comments and suggestions.
.PP
.I xgraph
accepts a large number of options most of which can be specified
either on the command line, in the user's .Xdefaults or .Xresources file, 
or in the data files themselves.
A list of these options is given below.  The command line
option is specified first with its X default or data file name (if any) 
in parenthesis afterward.
The format of the option in the X defaults file is "program.option: value"
where program is the program name (xgraph) and the option name is the
one specified below.
Option specifications in the data file are similar to the X defaults file
specification except the program name is omitted.
.TP
.B  \-geometry WxH+X+Y or \=WxH+X+Y (Geometry)
Specifies the initial size and location of the xgraph window.
.TP
.B  \-<digit> <name>
These options specify the data set name for the corresponding data set.
The digit should be in the range '0' to '63'.
This name will be used in the legend.
.TP
.B  \-bar (BarGraph)
Specifies that vertical bars should be drawn from the data points to
a base point which can be specified with -brb.  Usually,  the -nl
flag is used with this option.  The point itself is located at
the center of the bar.
.TP
.B  \-bof (BarGraph)
Offset the bars for additional datasets by the specified amount.
.TP 
.B  \-device <name>
Set the output device for xgraph. The default is 'X'; other valid
devices are 'ps', 'hpgl', 'idraw' and tgif.
.TP
.B  \-o <filename> \-O <filename>
Set the output file name for postscript, hpgl and idraw devices.
Files created with -O can be used other documents, and files generated
with -o can be printed directly.
.TP
.B  \-P<printername>
Set the printer name for postscript or hpgl devices. This and the -o or -O
option are mutually exclusive.
.TP 
.B \-stk
Stack elements coming from different datasets, instead of plotting them
from the same baseline. Datasets must match exactly.
.TP 
.B \-fitx
Translate and scale the x data from all datasets to fit [0..1].
.B \-fity
Translate and scale the y data from all datasets to fit [0..1].
.TP
.B \-scale <factor>
Output scale factor for postscript, hpgl and idraw devices. The default
is 1.0, and 0.5 will generate a 50% reduced plot.
.TP
.B \-fmtx <printf-format> \-fmty <printf-format>
Use the format specified to generate the legents for the x or y axis.
.TP
.B  \-bb (BoundBox)
Draw a bounding box around the data region.  This is very useful
if you prefer to see tick marks rather than grid lines (see -tk).
.TP
.B  \-bd <color> (Border)
This specifies the border color of the
.I xgraph
window.
.TP
.B  \-bg <color> (Background)
Background color of the
.I xgraph
window.
.TP
.B  \-brb <base> (BarBase)
This specifies the base for a bar graph.  By default,  the base is zero.
.TP
.B  \-brw <width> (BarWidth)
This specifies the width of bars in a bar graph.  The amount is specified
in the user's units.  By default,  a bar one pixel wide is drawn.
.TP
.B  \-bw <size> (BorderSize)
Border width (in pixels) of the
.I xgraph
window.
.TP
.B  \-db (Debug)
Causes xgraph to run in synchronous mode and prints out the values
of all known defaults.
.TP
.B  \-fg <color> (Foreground)
Foreground color.  This color is used to draw all text and the normal
grid lines in the window.
.TP
.B  \-gw (GridSize)
Width,  in pixels,  of normal grid lines.
.TP
.B  \-gs (GridStyle)
Line style pattern of normal grid lines.
.TP
.B  \-lf <fontname> (LabelFont)
Label font.  All axis labels and grid labels are drawn using this font.
A font name may be specified exactly (e.g. "9x15" or 
"-*-courier-bold-r-normal-*-140-*") or in an abbreviated form: <family>-<size>.
The family is the family name (like helvetica) and the size is the font
size in points (like 12).  The default for this parameter is "helvetica-12".
.TP
.B  \-lnx (LogX)
Specifies a logarithmic X axis.  Grid labels represent powers of ten.
.TP
.B  \-lny (LogY)
Specifies a logarithmic Y axis.  Grid labels represent powers of ten.
.TP
.B  \-lw width (LineWidth)
Specifies the width of the data lines in pixels.  The default is zero.
.TP
.B  \-lx <xl,xh> (XLowLimit, XHighLimit)
This option limits the range of the X axis to the specified
interval.  This (along with -ly) can be used to "zoom in" on a particularly
interesting portion of a larger graph.
.TP
.B  \-ly <yl,yh> (YLowLimit, YHighLimit)
This option limits the range of the Y axis to the specified
interval.
.TP
.B  \-m (Markers)
Mark each data point with a distinctive marker.
There are eight distinctive markers used by xgraph.
These markers are assigned uniquely to each different line style on
black and white machines and varies with each color on color machines.
.TP
.B  \-M (StyleMarkers)
Similar to -m but markers are assigned uniquely to each eight consecutive
data sets (this corresponds to each different line style on color machines).
.TP
.B  \-nl (NoLines)
Turn off drawing lines.  When used with -m, -M, -p, or -P this can be used to
produce scatter plots.  When used with -bar,  it can be used to
produce standard bar graphs.
.TP
.B  \-ng (NoLegend)
Turn off drawing Legends. Can be used to increase the drawing area.
.TP
.B  \-p (PixelMarkers)
Marks each data point with a small marker (pixel sized).  This is
usually used with the -nl option for scatter plots.
.TP
.B  \-P (LargePixels)
Similar to -p but marks each pixel with a large dot.
.TP
.B  \-rv (ReverseVideo)
Reverse video.  On black and white displays,  this will invert
the foreground and background colors.  
The behaviour on color displays is undefined.
.TP
.B  \-t <string> (TitleText)
Title of the plot.  This string is centered at the top of the graph.
.TP
.B  \-tf <fontname> (TitleFont)
Title font.  This is the name of the font to use for the graph title.
A font name may be specified exactly (e.g. "9x15" or 
"-*-courier-bold-r-normal-*-140-*") or in an abbreviated form: <family>-<size>.
The family is the family name (like helvetica) and the size is the font
size in points (like 12).  The default for this parameter is "helvetica-18".
.TP
.B  \-tk (Ticks)
This option causes
.I xgraph
to draw tick marks rather than full grid lines.  The -bb option
is also useful when viewing graphs with tick marks only.
.TP
.B  \-tkax (Tick Axis)
When tick marks are enabled, plot the axes.
.TP
.B  \-x <unitname> (XUnitText)
This is the unit name for the X axis.  Its default is "X".
.TP
.B  \-y <unitname> (YUnitText)
This is the unit name for the Y axis.  Its default is "Y".
.TP
.B  \-zg <color> (ZeroColor)
This is the color used to draw the zero grid line.
.TP
.B  \-zw <width> (ZeroWidth)
This is the width of the zero grid line in pixels.
.PP
Some options can only be specified in the X defaults file or in the
data files.  These options are described below:
.TP
.B <digit>.Color
Specifies the color for a data set.  Eight independent colors can
be specified.  Thus,  the digit should be between '0' and '7'.
If there are more than eight data sets,  the colors
will repeat but with a new line style (see below).
.TP
.B <digit>.Style
Specifies the line style for a data set.  A string of ones
and zeros specifies the pattern used for the line style.
Eight independent line styles can be specified.  Thus,  the
digit should be between '0' and '7'.  If there are more
than eight data sets,  these styles will be reused.  On color
workstations,  one line style is used for each of eight colors.
Thus,  64 unique data sets can be displayed.
.TP
.B Device
The default output form presented in the hardcopy dialog (i.e. "Postscript",
"HPGL", etc).
.TP
.B Disposition
The default setting of whether output goes directly to a device or to a file.  
This must be one of the strings "To File" or "To Device".
.TP
.B FileOrDev
The default file name or device string in the hardcopy dialog.
.TP
.B ZeroWidth
Width,  in pixels,  of the zero grid line.
.TP
.B ZeroStyle
Line style pattern of the zero grid line.
.SH AUTHOR
David Harrison
University of California
.SH BUGS
.br
- Zooming in on bar graphs doesn't work right.
.br
- There is no way to produce hardcopy without running xgraph interactively.