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NAME
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grap – pic preprocessor for drawing graphs
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SYNOPSIS
DESCRIPTION
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Grap is a pic(1) preprocessor for drawing graphs on a typesetter.
Graphs are surrounded by the troff ‘commands’ .G1 and .G2. Data
are scaled and plotted, with tick marks supplied automatically.
Commands exist to modify the frame, add labels, override the default
ticks, change the plotting style, define coordinate ranges and
transformations, and
include data from files. In addition, grap provides the same loops,
conditionals, and macro processing that pic does.
frame ht e wid e top dotted ...: Set the frame around the graph
to specified ht and wid; default is 2 by 3 (inches). The line
styles (dotted, dashed, invis, solid (default)) of the sides (top,
bot, left, right) of the frame can be set independently.
label side "a label" "as a set of strings" adjust: Place label on
specified side; default side is bottom. adjust is up (or down
left right) expr to shift default position; width expr sets the
width explicitly.
ticks side in at optname expr, expr, ...: Put ticks on side at
expr, ..., and label with "expr". If any expr is followed by "...",
label tick with "...", and turn off all automatic labels. If "..."
contains %f’s, they will be interpreted as printf formatting instructions
for the tick value. Ticks point in or out (default out). Tick
iterator: instead of at ..., use from expr
to expr by op expr where op is optionally +−*/ for additive or
multiplicative steps. by can be omitted, to give steps of size
1. If no ticks are requested, they are supplied automatically;
suppress this with ticks off. Automatic ticks normally leave a
margin of 7% on each side; set this to anything by margin = expr.
grid side linedesc at optname expr, expr, ...: Draw grids perpendicular
to side in style linedesc at expr, .... Iterators and labels work
as with ticks.
coord optname x min, max y min, max log x log y: Set range of
coords and optional log scaling on either or both. This overrides
computation of data range. Default value of optname is current
coordinate system (each coord defines a new coordinate system).
plot "str" at point; "str" at point: Put str at point. Text position
can be qualified with rjust, ljust, above, below after "...".
line from point to point linedesc: Draw line from here to there.
arrow works in place of line.
next optname at point linedesc: Continue plot of data in optname
to point; default is current.
draw optname linedesc ...: Set mode for next: use this style from
now on, and plot "..." at each point (if given).
new optname linedesc ...: Set mode for next, but disconnect from
previous.
A list of numbers x y1 y2 y3 ... is treated as plot bullet at
x,y1; plot bullet at x,y2; etc., or as next at x,y1 etc., if draw
is specified. Abscissae of 1,2,3,... are provided if there is
only one input number per line.
A point optname expr, expr maps the point to the named coordinate
system. A linedesc is one of dot dash invis solid optionally followed
by an expression.
define name {whatever}: Define a macro. There are macros already
defined for standard plotting symbols like bullet, circle, star,
plus, etc., in /home/opt/plan9port/lib/grap.defines, which is
included if it exists.
var = expr: Evaluate an expression. Operators are + − * and /.
Functions are log and exp (both base 10), sin, cos, sqrt; rand
returns random number on [0,1); max(e,e), min(e,e), int(e).
print expr; print "...": As a debugging aid, print expr or string
on the standard error.
copy "file name": Include this file right here.
copy thru macro: Pass rest of input (until .G2) through macro,
treating each field (non-blank, or "...") as an argument. macro
can be the name of a macro previously defined, or the body of
one in place, like /plot $1 at $2,$3/.
copy thru macro until "string": Stop copy when input is string (left-justified).
pic remainder of line: Copy to output with leading blanks removed.
graph Name pic-position: Start a new frame, place it at specified
position, e.g., graph Thing2 with .sw at Thing1.se + (0.1,0).
Name must be capitalized to keep pic happy.
.anything at beginning of line: Copied verbatim.
sh %anything %: Pass everything between the %’s to the shell;
as with macros, % may be any character and anything may include
newlines.
# anything: A comment, which is discarded.
Order is mostly irrelevant; no category is mandatory. Any arguments
on the .G1 line are placed on the generated .PS line for pic.
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EXAMPLES
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.G1
frame ht 1 top invis right invis
coord x 0, 10 y 1, 3 log y
ticks left in at 1 "bottommost tick", 2,3 "top tick"
ticks bot in from 0 to 10 by 2
label bot "silly graph"
label left "left side label" "here"
grid left dashed at 2.5
copy thru / circle at $1,$2 /
1 1
2 1.5
3 2
4 1.5
10 3
.G2
frame ht 1 top invis right invis
coord x 0, 10 y 1, 3 log y
ticks left in at 1 "bottommost tick", 2,3 "top tick"
ticks bot in from 0 to 10 by 2
label bot "silly graph"
label left "left side label" "here"
grid left dashed at 2.5
copy thru / circle at $1,$2 /
1 1
2 1.5
3 2
4 1.5
10 3
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FILES
SOURCE
SEE ALSO
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pic(1), troff(1)
J. L. Bentley and B. W. Kernighan, “GRAP--A Language for Typesetting
Graphs”, Unix Research System Programmer’s Manual, Tenth Edition,
Volume 2.
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