| GRAP(1) | GRAP(1)

NAME

| grap – pic preprocessor for drawing graphs

SYNOPSIS

| `grap` [ file ... ]

DESCRIPTION

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 `/usr/local/plan9/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.

EXAMPLES

`.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
`

FILES

| `/usr/local/plan9/lib/grap.defines` definitions of standard plotting characters, e.g., bullet

SOURCE

| `/usr/local/plan9/src/cmd/grap`

SEE ALSO

| 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.