PGPLOT driver for PostScript printers
The PostScript page description language is widely used for desktop
publishing. PostScript files can be printed on many laser printers and
photo-typesetters, and they can also be viewed on most workstations
ghostview on UNIX workstations,
pageview on Sun workstations,
view/format=ps/interface=decw on VMS workstations). A
single-page PGPLOT PostScript file is valid ``encapsulated
PostScript'' and can be included in another file by way of a
page-composition program. PGPLOT generates level-1 PostScript which is
accepted by all PostScript printers. PostScript is a trademark of
Adobe Systems Incorporated.
Device type code
``Color'' PostScript files can be printed on monochrome printers: the
colors will be rendered as shades of grey. Use the monochrome codes
(/PS, /VPS) when you know that the file is to be printed only on
/PS (monochrome landscape mode, long edge of paper horizontal).
/CPS (color landscape mode, long edge of paper horizontal).
/VPS (monochrome portrait mode, short edge of paper horizontal).
/VCPS (color portrait mode, short edge of paper horizontal).
Default file name
If a file name of
- is specified (e.g.,
PostScript file is sent to the standard output stream (stdout in UNIX).
Default view surface dimensions
10.5 inches horizontal by 7.8 inches vertical (landscape mode);
7.8 inches horizontal by 10.5 inches vertical (portrait mode).
These dimensions can be changed with environment variables.
The driver uses coordinate increments of 0.001 inch, giving an
``apparent'' resolution of 1000 pixels/inch. The true resolution is
device-dependent; e.g., on an Apple LaserWriter it is 300 pixels/inch
(in both dimensions).
Color indices 0--255 are supported, and the color representation
can be changed with routine
PGSCR. With device types /PS
and /VPS, color index 0 is white (erase or background color), indices
1--13 are black, 14 is light grey, and 15 is dark grey; while with
device types /CPS and /VCPS, color index 0 is white (erase or
background color), index 1 is black, and indices 2--15 have the
standard PGPLOT color assignments.
The file contains variable length records (maximum 132 characters)
containing PostScript commands. The commands use only printable ASCII
characters, and the file can be examined or modified with a text
Use the operating system print or copy command to send the file to
a suitable PostScript printer.
PGPLOT_PS_WIDTH (default 7800)
PGPLOT_PS_HEIGHT (default 10500)
PGPLOT_PS_HOFFSET (default 350)
PGPLOT_PS_VOFFSET (default 250)
- These variables tell PGPLOT how big an image to produce. The defaults
are appropriate for 8.5 x 11-inch paper. The maximum dimensions of
a PGPLOT image are WIDTH by HEIGHT, with the lower left corner offset
by HOFFSET horizontally and VOFFSET vertically from the lower left
corner of the paper. The units are milli-inches. The ``top'' of the
paper is the edge that comes out of the printer first.
- If this variable is defined (with
any value), the user name, date and time are written in the bottom
right corner of each page.
- Normally, PGPLOT computes the
bounding box for the entire plot (the smallest rectangle that includes
all the graphics) as it creates the PostScript file, and writes this
information in a %%BoundingBox comment in the file trailer. Some
programs that read encapsulated PostScript files expect to find the
%%BoundingBox comment in the file header, not the trailer, and may not
display the plot correctly. To fix this problem, you may need to move
the comment from the trailer to the header with a text editor or
special program. Alternatively, you can define
MAX. This tells PGPLOT to put a %%BoundingBox comment in the
header of the PostScript file; the bounding box is one which
encompasses the whole plottable area, not a minimal one, because PGPLOT
does not know the correct bounding box until it has finished writing
- If this variable is set, the
bounding box (the smallest rectangle that includes all the graphics)
is drawn on each page.
- If this variable is set, the text of each plotted character string is
included in the PostScript file as a comment before the sequence of
vectors that represents the string. This makes the file slightly larger, but
it can be useful if you want to edit
the PostScript file.
- Normally the output file does not contain special end-of-file
characters. But if environment variable PGPLOT_PS_EOF is defined
(with any value) PGPLOT writes a control-D job-separator character at
the beginning and at the end of the file. This is appropriate for
Apple LaserWriters using the serial interface, but it may not be
appropriate for other PostScript devices.
NO to suppress use of a PostScript font for
the graph markers; markers are then emulated by line-drawing. If this
option is not requested, PGPLOT graph markers are scaled geometrically
with the character-height attribute and the line-width attribute is
ignored. This is different from most of the other drivers, where the
line-width used for markers is set by the line-width attribute rather
than the character-height attribute. Requesting this option makes the
PostScript driver behave like the other drivers, but it also makes
the PostScript files larger.
Document Structuring Conventions
The PostScript files conform to Version 3.0 of the Adobe Document
Structuring Conventions (see ref.3) and to version 3.0 of the
encapsulated PostScript file (EPSF) format. This should allow the
files to be read by other programs that accept the EPSF format. Note,
though, that multi-page plots are not valid EPSF files. The files do
not contain a screen preview section. A device-independent screen
preview can be added to PGPLOT files with the program ps2epsi
by George Cameron, available with the GhostScript
PostScript interpreter from Aladdin Enterprises.
Note that a valid EPSF file should have a %%BoundingBox comment in the
header of the file. By default, PGPLOT puts the comment in the trailer
of the file, where some but not all programs will find it. You may
need to move this comment into the file header using a text editor or
special program. See also the discussion of the environment variable
- Adobe Systems, Inc.: PostScript Language Reference Manual.
Addison-Wesley, Reading, Massachusetts, 1985.
- Adobe Systems, Inc.: PostScript Language Tutorial and Cookbook.
Addison-Wesley, Reading, Massachusetts, 1985.
- Adobe Systems, Inc.: PostScript Language Reference Manual, Second
Edition. Addison-Wesley, Reading, Massachusetts, 1990.
T. J. Pearson, 1991--1995.