.BG
.FN pic
.TL
Device Driver for Pic Troff Preprocessor
.CS
pic(file, command)
.AG file
character string naming a file.
If this argument is supplied, the output pic text will be written
to this file.
.AG command
character string naming a Unix command.
If `file' is not supplied, the device driver output will be piped
through `command'.
The default value of command will be installation
dependent, and might reasonably include a call to pic, troff, and
an appropriate laser printer spooler.
.PP
This function is a graphics device driver that produces a set of commands
for the pic troff preprocessor. 
By default the commands are piped
through pic and troff, and output on an appropriate printer.
This is done via a default `command' argument.
When the `file' argument is given, the text is instead
saved on the named file.
If the specified file already exists, it will be overwritten.
.PP
The `pic' driver supports variable character sizes (up to `cex=6'),
string rotation (but not character rotation), a large number of different
line styles and line widths. 
Line styles are interpreted as dashed (`lty>1')
or dotted (`lty<0'). Line widths are specified as some number between
0.1 and 6, with `lwd<1' specifying a line thinner than the default, and
`lwd>1' specifying a line thicker than the default.
.PP
The `pic' driver does not support colors or font changes.
.PP
When `pch=' is used to specify a plotting character, only the "*" and
"." characters are guaranteed to be centered over the plotted point.
.PP
When graphic input (`identify', `locator') is requested, the prompt
`x,y:' appears on the users terminal, and the user should type the
(x,y) coordinate pair of the point to be input.  To terminate the
input, hit carriage return.  Graphic input is not allowed in batch
mode.
.PP
The output may contain more than one picture, each bracketed
by ".PS/.PE" lines.
Since the file is ASCII text, it can be read and edited by the user.
.PP
A device must be specified before any graphics functions can be used.
.EX
pic()	# send to default printer

pic(command="pic -Taps | troff -Taps | lp -d aps")
	# send to a different printer

pic("Pic.In")	# generate file for later processing
.KW device
.WR
