bgraph  do a set of batch graphs to a metafile
bgraph [ type .. ][ +variable value .. ][ file .. ]
Bgraph reads each graph file in sequence and converts it to a plot suitable for use by a metafile driver program. If no files are given, the standard input is read.
The graph type can be defined with a type option. Types are simply include files which set default values for certain variables. The actual include file name is the type concatanated with ".plt". Typical types are "scatter", "line", and "curve". A scatter graph shows only points. A line graph shows only lines connecting points. A curve graph shows both points and connecting lines.
Variables can be set explicitly with +variable value options. The following standard graph variables are supported:
fthick 
The frame thickness, valued from 0 to 4. A value of 0 turns the frame off. 

grid 
The grid: 1 is on, 0 is off. 

include 
The include file name. Graph input is taken from the file. If the file is not found in the current directory, it is searched for in a set of standard locations. 

legend 
The legend title. 

othick 
The origin axis thickness, valued from 0 to 4. A value of 0 turns the origin off. 

period 
The period for a polar plot. For a plot in degrees, use 360. For radians, use 6.283. A value of 0 (the default) indicates a Cartesian plot. 

subtitle 
The graph subtitle. 

symfile 
The point symbol metafile. 

tstyle 
The frame tick mark style. The default value is 1, which is outward tick marks. A value of 2 is inward ticks, 3 is cross ticks. A value of 0 disables frame tick marks. 

title 
The graph title. 

xlabel 
The x axis label. 

xmap 
The x axis mapping function. An x axis mapping xmap(x)=log(x) produces a log x axis. 

xmax 
The x axis maximum. 

xmin 
The x axis minimum. 

xstep 
The x axis step. 

ylabel 
The y axis label. 

ymap 
The y axis mapping function. An y axis mapping ymap(y)=log(y) produces a log y axis. 

ymax 
The y axis maximum. 

ymin 
The y axis minimum. 

ystep 
The y axis step. 
In addition to the standard graph variables, each curve has a set of variables. The variables for curve ’A’ all begin with the letter ’A’; the variables for curve ’B’ all begin with the letter ’B’, and so on. Up to 8 curves are supported on a single graph, ’A’ through ’H’. The variables for curve ’A’ are:
A 
The function for curve ’A’. If Adata is undefined, xmin, xmax and Anpoints are used to determine which x values to plot. If Adata is defined and A is a function of a single variable (ie. A(x)), data values are interpreted as x values to be plotted. If Adata is defined and A is a function of two variables (ie. A(x,y)), data values are interpreted as (x,y) pairs and A becomes a mapping function for the data. 

Acolor 
The color for curve A. The values 14 map to black, red, green, and blue respectively. A value of 0 turns curve A off. 

Adata 
The point data for curve ’A’. If Adata is set to the name of a file, data is read and interpreted from that file. If Adata is set to a command (beginning with an exclamation, ’!’), the output of the command is read as data. Otherwise, data is read from the current file. Data values are separated by white space and/or commas. A semicolon or end of file indicates the end of data. 

Alabel 
The label for curve ’A’. The curve label is printed in the legend when a curve is defined. 

Alintype 
The line type for curve ’A’, valued from 0 to 4. A value of 0 turns line drawing off. A value of 1 is solid, 2 is dashed, 3 is dotted, and 4 is dotdashed. 

Anpoints 
The number of symbol points for curve ’A’. If Adata is defined, all points will be connected with the selected curve line, but only Anpoints points will be indicated with a symbol. This prevents messy graphs when large number of points are defined. If A is defined and Adata is not, Anpoints is used along with xmin and xmax to determine which x values to plot. 

Asymsize 
The symbol radius for curve ’A’. The default size is 100. A value of 0 turns symbols off. 

Asymtype 
This is the name of a segment in symfile which defines the graphics symbol for curve ’A’. 

Athick 
The line thickness for curve ’A’, valued from 0 to 4. A thickness of 0 turns line drawing off. 
A graph file contains definitions for graph and curve variables. These definitions fall one per line in the following formats:
vreal = expression # real variable 

vfunction(x) = expression(x) # function 

vstring = "string" # string variable 

vdata = filename # data file 

vdata = "!command" # data generator 

variable = continued \ 

line # newline escaped 

vdata = # data 

v1 v2 v3 v4 ... ; 
Comments are preceded by a ’#’, and continue to the end of the line. Except for comments, the newline can be escaped with a backslash. Note that in the special case where data is contained in the graph file, a definition will continue over more than one line. Data values can be separated by commas or white space, and reading continues until a semicolon is reached. No comments are allowed in the data section of a file.
An expression is an algebraic formula containing numbers, variables, functions, and the standard operators {+,,*,/,^,(,)} (see icalc(1)). Besides the variables described in the last section, definitions of intermediate real variables and functions are allowed for convenience. They may be used in expressions of graph and curve variables.
A file to graph the sine function is:
title = "Sine Function from 0 to Pi" 

PI = 3.141592653589793 

A(x) = sin(x) 

xmin = 0 

xmax = PI 

Anpoints = 100 
Or, to graph selected points:
title = "Sine Function at 0, .2, .6, and .8" 

A(x) = sin(x) 

Adata = 

0 , .2 

.6 , .8 

; 
The commands to plot these files might be:
bgraph line sine1.plt  psmeta  lpr 

bgraph curve +ymin 1 +ymax 1 sine2.plt  x11meta 
/usr/local/lib/meta/*.mta /usr/local/lib/meta/*.plt *.plt
Greg Ward
There is no mechanism provided for undefining a variable. An axis mapping function which is not invertible (monotonically increasing or decreasing) confuses the program terribly.
dgraph(1), gcomp(1), icalc(1), igraph(1), metafile(5), x11meta(1)