reads each graph
in sequence and converts it to a character plot
displayable on any ascii device.
If no files are given, the standard input is read.
Across the top of the plot, the extrema are printed.
This is the only indication of the axis size.
Curves are represented with their respective letter ('A' for
curve A, etc.) at each point.
Where two or more curves cross, a number is shown instead.
The size of the output array can be specified as a
The default size is 79 by 22.
Variables can be set explicitly with
See bgraph(1) for details.
To get a quick glimpse of the sine function from 0 to 4.
There is no mechanism provided for undefining a variable.