PLOT(6)PLOT(6)

NAME

plot – graphics interface

DESCRIPTION

Files of this format are interpreted by plot(1) to draw graphics on the screen. A plot file is a UTF stream of instruction lines. Arguments are delimited by spaces, tabs, or commas. Numbers may be floating point. Punctuation marks (except :) , spaces, and tabs at the beginning of lines are ignored. Comments run from : to newline. Extra letters appended to a valid instruction are ignored. Thus ...line, line,and li all mean the same thing. Arguments are interpreted as follows:

1.

If an instruction requires no arguments, the rest of the line is ignored.  

2.

If it requires a string argument, then all the line after the first field separator is passed as argument. Quote marks may be used to preserve leading blanks. Strings may include newlines represented as \n.  

3.

Between numeric arguments alphabetic characters and punctuation marks are ignored. Thus line from 5 6 to 7 8 draws a line from (5, 6) to (7, 8).  

4.

Instructions with numeric arguments remain in effect until a new instruction is read. Such commands may spill over many lines. Thus the following sequence will draw a polygon with vertices (4.5, 6.77), (5.8, 5.6), (7.8, 4.55), and (10.0, 3.6).  

 

move 4.5 6.77
vec 5.8, 5.6 7.8
4.55 10.0, 3.6 4.5, 6.77

The instructions are executed in order. The last designated point in a line, move , rmove , vec, rvec , arc , or point command becomes the ‘current point’ (X,Y) for the next command.

Open & Close

o string

Open plotting device. For troff, string specifies the size of the plot (default is 6i).  

cl

Close plotting device.  

Basic Plotting Commands

e

Start another frame of output.  

m x y

(move) Current point becomes x y.  

rm dx dy

Current point becomes X+dx Y+dy.  

poi x y

Plot the point x y and make it the current point.  

v x y

Draw a vector from the current point to x y.  

rv dx dy

Draw vector from current point to X+dx Y+dy  

li x1 y1 x2 y2

Draw a line from x1 y1 to x2 y2. Make the current point x2 y2.  

t string

Place the string so that its first character is centered on the current point (default). If string begins with \C (\R), it is centered (right-adjusted) on the current point. A backslash at the beginning of the string may be escaped with another backslash.  

a x1 y1 x2 y2 xc yc r

Draw a circular arc from x1 y1 to x2 y2 with center xc yc and radius r. If the radius is positive, the arc is drawn counterclockwise; negative, clockwise. The starting point is exact but the ending point is approximate.  

ci xc yc r

Draw a circle centered at xc yc with radius r. If the range and frame parameters do not specify a square, the ‘circle’ will be elliptical.  

di xc yc r

Draw a disc centered at xc yc with radius r using the filling color (see cfill below).  

bo x1 y1 x2 y2

Draw a box with lower left corner at x1 y1 and upper right corner at x2 y2.  

sb x1 y1 x2 y2

Draw a solid box with lower left corner at x1 y1 and upper right corner at x2 y2 using the filling color (see cfill below).  

par x1 y1 x2 y2 xg yg

Draw a parabola from x1 y1 to x2 y2 ‘guided’ by xg yg. The parabola passes through the midpoint of the line joining xg yg with the midpoint of the line joining x1 y1 and x2 y2 and is tangent to the lines from xg yg to the endpoints.  

pol { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

Draw polygons with vertices x1 y1 ... xn yn and X1 Y1 ... Xm Ym. If only one polygon is specified, the inner brackets are not needed.  

fi { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

Fill a polygon. The arguments are the same as those for pol except that the first vertex is automatically repeated to close each polygon. The polygons do not have to be connected. Enclosed polygons appear as holes.  

sp { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

Draw a parabolic spline guided by x1 y1 ... xn yn with simple endpoints.  

fsp { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

Draw a parabolic spline guided by x1 y1 ... xn yn with double first endpoint.  

lsp { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

Draw a parabolic spline guided by x1 y1 ... xn yn with double last endpoint.  

dsp { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

Draw a parabolic spline guided by x1 y1 ... xn yn with double endpoints.  

csp { { x1 y1 ... xn yn } ... { X1 Y1 ... Xm Ym} }

 

in filename

(include) Take commands from filename.  

de string { commands }

Define string as commands.  

ca string scale

Invoke commands defined as string applying scale to all coordinates.  

Commands Controlling the Environment

co string

Use color given by first character of string, one of red, yellow, green, blue, cyan, magenta, white, and kblack.  

pe string

Use string as the style for drawing lines. The available pen styles are: solid, dott[ed], short, long, dotd[ashed], cdash, ddash  

cf string

Color for filling (see co, above).  

ra x1 y1 x2 y2

The data will fall between x1 y1 and x2 y2. The plot will be magnified or reduced to fit the device as closely as possible.  

Range settings that exactly fill the plotting area with unity scaling appear below for devices supported by the filters of plot(1). The upper limit is just outside the plotting area. In every case the plotting area is taken to be square; points outside may be displayable on devices with nonsquare faces.  

fr px1 py1 px2 py2

Plot the data in the fraction of the display specified by px1 py1 for lower left corner and px2 py2 for upper right corner. Thus frame .5 0 1. .5 plots in the lower right quadrant of the display; frame 0. 1. 1. 0. uses the whole display but inverts the y coordinates.  

sa

Save the current environment, and move to a new one. The new environment inherits the old one. There are 7 levels.  

re

Restore previous environment.  

SEE ALSO

plot(1), graph(1)