The input format is similar to graph(1G) but differs slightly. The data consists of a number of 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.
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
After 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.
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. xgraph will then open a new window looking at just that portion of the graph. xgraph also presents three control buttons in the upper left corner of each window: Close, Hardcopy, and About. Windows are closed by depressing a mouse button while the mouse cursor is inside the Close button. Typing EOF (control-D) in a window also closes that window. Depressing a mouse button while the mouse cursor is in the Hardcopy button causes a dialog to appear asking about hardcopy (printout) options. These options are described below:
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.
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.
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.
Maximum Dimension
This specifies the maximum size of the plot on the
hardcopy device in centimeters. 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.
Include in Document
If selected, this option causes 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.
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.
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.
Axis Font Family and Axis Font Size
These fields are like Title Font Family and Title Font
Size except they specify values for the font xgraph
uses to draw axis labels, and legend descriptions.
Control Buttons
After specifing the parameters for the plot, the "Ok"
button causes xgraph to produce a hardcopy. Pressing
the "Cancel" button will abort the hardcopy operation.
Depressing the 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.
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.
=WxH+X+Y (Geometry)
Specifies the initial size and location of the xgraph
window. -<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.
<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).
<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.
Device
The default output form presented in the hardcopy dialog
(i.e. "Postscript", "HPGL", etc).
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".
FileOrDev
The default file name or device string in the hardcopy
dialog.
ZeroWidth
Width, in pixels, of the zero grid line.
ZeroStyle
Line style pattern of the zero grid line.