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Commands Reference, Volume 2
Typesets graphs to be processed by
the pic command.
grap [ -l ]
[ -T Name ] [ -- ] [ File
... ]
The grap command
processes grap language input files and generates input to the pic command. The grap language is a
language for typesetting graphs. A typical command line is:
grap File | pic | troff | Typesetter
Graphs are surrounded by the
.G1 and .G2 troff command requests.
Data enclosed by these requests are scaled and plotted, with tick marks
automatically supplied. 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,
the grap command provides the same loops, conditionals, and
macroprocessing as the pic command.
Grap language files contain grap
programs. A grap program is written in the form:
.G1
grap Statement
grap Statement
grap Statement
.G2
| File
| Specifies grap language files (grap programs) to be processed by the
grap command for input to the pic command.
|
Following is a summary of the grap
statements you can use to create a grap program:
| frame
| Defines the frame that surrounds the graph. The syntax is:
frame [ht Expression] [wid Expression] [[Side] LineDescription]
|
The attributes are defined as
follows:
- Side:
top, bot, left, right
- LineDescription: solid,
invis, dotted [Expression],
dashed [Expression]
Height defaults to 2 inches,
width defaults to 3 inches, sides default to solid. If side
is omitted, the linedesc applies to the entire frame.
| label
| Places a label on a specified side of the graph. The syntax
is:
label Side StringList ... Shift
|
The attributes are defined as
follows:
- Shift:
left, right, up, or down
expression
- StringList: str
... rjust, ljust, above,
below [size
(+)Expression]
...
- String:
"..."
| coord
| Defines an overriding system. The syntax is:
coord [Name] [x Expression,Expression] [y Expression,Expression] [[log x] [log y] [log log]]
|
| ticks
| Places tick marks on one side of the frame. The syntax is:
ticks side [[in] [out] [Expression]] [Shift] [TickLocations]
|
The attributes are defined as
follows:
- Shift:
left, right, up, down
Expression
- TickLocations: at [Name]
Expression [String], Expression
[String], ... from [Name]
Expression to Expression [by [Operation]
Expression] String
If no ticks are specified, they
will be provided automatically; ticks off suppresses automatic
ticks.
| grid
| Produces grid lines along (that is, perpendicular to) the named
side. The syntax is:
grid Side [LineDescription] [Shift] [TickLocations]
|
Grids are labeled by the same
mechanism as ticks.
| plot
| Places text at a point. The syntax is:
StartList at Point plot Expression [Start] at Point
|
The attributes are defined as
follows:
- StringList: str
... rjust, ljust, above,
below [size
+)Expression] ...
- Point:
[Name] Expression
Expression
| line
| Draws a line or arrow from one point to another. The syntax
is:
{line | arrow} from Point to Point [LineDescription]
|
The attributes linedesc are
defined as follows:
- Point:
[Name] Expression Expression
- LineDescription: solid,
invis, dotted
[Expression], dashed
Expression]
| circle
| Draws a circle. The syntax is:
circle at Point [radius Expression]
|
The radius is in inches; the
default size is small.
| draw
| Defines a sequence of lines. The syntax is:
draw [Name] at Point[LineDescription]
|
| next
| Continues a sequence. The syntax is:
next [Name] at Point [LineDescription]
|
| new
| Starts a new sequence. The syntax is:
new [Name] at Point [LineDescription]
|
| numberlist
| Creates a line from a given set of numbers. The numbers are
treated as points x, y1, y2, and so on;
and plotted at the single x value. The syntax is:
number x, y1, y2 ...
|
| for
| Creates a loop. The syntax is:
for Variable {from | =} Expression to Expression [by [arithmetic or multiplicative operator] Expression] do X Anything X
X is any single character that
does not appear in the string. If X is a left brace {, then
the string may contain internally balanced braces followed by a right
brace}. The text Anything is repeated as the
Variable takes on values from the first Expression to
the second Expression.
|
| if
| Creates a conditional evaluation. The syntax is:
if Expression then X Anything X [else X Anything X]
|
| define
| Provides the same macroprocessor that Priority Interrupt Controller (PIC)
does. The syntax is:
define MacroName X Anything X
|
| copy
| Copies a file; includes the current contents of the file. The
syntax is:
copy Filename
|
| copy-thru
| Copies the file through the macro.
copy Filename thru MacroName
Each number or quoted string is
treated as an argument. Copying continues until end of file or the next
.G2. The optional clause until
String causes copying to stop when a line whose first field is
String occurs.
The following statement copies
subsequent lines through the macro:
copy thru MacroName
In all cases, you can specify the
macro by inline rather than by name:
copy thru x MacroBody x
|
| sh
| Passes text through to the UNIX shell. The syntax is:
sh x Anything x
The variable Anything
is scanned for macros. The pid macro is built-in. It
is a string consisting of the process identification number; you can use
it to generate unique file names.
|
| pic
| Passes text through to pic with the pic
removed. Variables and macros are not evaluated. Lines beginning
with a period (that are not numbers) are passed through literally, under the
assumption that they are troff commands.
|
| graph
| Defines a new graph named Picname, and resets all coordinate
systems. The syntax is:
graph Picname [pic-text]
If graph commands are
used in a grap program, the statement after the .G1 must be
a graph command. You can use the pic-text to
position this graph relative to previous graphs by referring to their Frames
as in the following example.
graph First
...
graph Second with .Frames.w at First.Frame.e + [0.1,0]
Macros and expressions in
pic-text are not evaluated. Picnames must begin
with a capital letter according to pic syntax.
|
| print
| Writes on stderr as grap processes its input. This
statement can be helpful in debugging. The syntax is:
print [Expression | String]
|
The following conventions
apply:
- The # (pound
sign) introduces a comment. The comment ends automatically at the end
of a line.
- Statements that
continue for more than one line must be preceded by a \ (backslash character)
at the beginning of each new line.
- Multiple statements
appearing on one line must be separated by semicolons.
- The grap language
ignores blank lines.
- Predefined strings
include bullet, plus, box, star,
dot, times, htick, vtick,
square, and delta.
- Built-in functions
available in grap include log (base 10), exp (base 10),
int, sin, cos, atan2,
sqrt, min, max, and rand.
| -l
| Stops the grap command from looking for the
/usr/lib/dwb/grap.defines library file of macro
definitions.
|
| -TName
| Specifies the value of the Name variable as the
grap command output device. The default value is
-Tibm3816.
|
| - -
| (Double dash) Indicates the end of flags.
|
| /usr/lib/dwb/grap.defines
| Contains definitions of standard plotting characters.
|
The pic command.
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