plot - plotting interface
Files of this format are produced by routines described in plot(3) and
are interpreted for various devices by commands described in plot(1). A
graphics file is a stream of plotting instructions. Each instruction consists
of an ASCII letter usually followed by bytes of binary information
(network-endian). The instructions are executed in order. A point is
designated by four bytes representing the x and y values; each value is a
signed integer. The last designated point in an l, m, n, a, or p
instruction becomes the `current point' for the next instruction. The a
and c instructions change the current point in a manner dependent upon
the specific device.
Each of the following descriptions begins with the name of the
corresponding routine in plot(3).
- m
- move: The next four bytes give a new current point.
- n
- cont: Draw a line from the current point to the point given by the next
four bytes.
- p
- point: Plot the point given by the next four bytes.
- l
- line: Draw a line from the point given by the next four bytes to the point
given by the following four bytes.
- t
- label: Place the following ASCII string so that its first character falls
on the current point. The string is terminated by a newline.
- a
- arc: The first four bytes give the center, the next four give the starting
point, and the last four give the end point of a circular arc. The least
significant coordinate of the end point is used only to determine the
quadrant. The arc is drawn counter-clockwise.
- c
- circle: The first four bytes give the center of the circle, the next two
the radius.
- e
- erase: Start another frame of output.
- f
- linemod: Take the following string, up to a newline, as the style for
drawing further lines. The styles are `dotted,' `solid,' `longdashed,'
`shortdashed,' and `dotdashed.' Effective only in plot 4014 and
plot ver.
- s
- space: The next four bytes give the lower left corner of the plotting
area; the following four give the upper right corner. The plot will be
magnified or reduced to fit the device as closely as possible.
- Space 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
whose face isn't square.
- 4013
- pl_space(0, 0, 780, 780);
- 4014
- pl_space(0, 0, 3120, 3120);
plot(1), plot(3), f77plot(3), graph(1)
A label instruction immediately followed by a cont instruction
does the wrong thing on a 4014.