GNUPlot Manual

128 gnuplot 4.0 36 SET-SHOW
You can escape control characters using \, e.g., \\, \{, and so on.
But be aware that strings in double-quotes are parsed differently than those enclosed in single-quotes.
The major difference is that backslashes may need to be doubled when in double-quoted strings.
Examples (these are hard to describe in words — try them!):
set xlabel ’Time (10^6 {/Symbol m}s)’
set title ’{/Symbol=18 \362@_{/=9.6 0}^{/=12 x}} \
{/Helvetica e^{-{/Symbol m}^2/2} d}{/Symbol m}’
The file "ps guide.ps" in the /docs/psdoc subdirectory of the gnuplot source distribution contains more
examples of the enhanced syntax.
36.59.55.2 Editing postscript The PostScript language is a very complex language — far too
complex to describe in any detail in this document. Nevertheless there are some things in a PostScript
file written by gnuplot that can be changed without risk of introducing fatal errors into the file.
For example, the PostScript statement "/Color true def" (written into the file in response to the command
set terminal postscript color), may be altered in an obvious way to generate a black-and-white version
of a plot. Similarly line colors, text colors, line weights and symbol sizes can also be altered in straightforward
ways. Text (titles and labels) can be edited to correct misspellings or to change fonts. Anything
can be repositioned, and of course anything can be added or deleted, but modifications such as these
may require deeper knowledge of the PostScript language.
The organization of a PostScript file written by gnuplot is discussed in the text file "ps file.doc" in the
docs/ps subdirectory of the gnuplot source distribution.
36.59.55.3 Postscript fontfile The fontfile or fontfile add option takes one file name as argument
and encapsulates this file into the postscript output in order to make this font available for text elements
(labels, tic marks, titles, etc.). The fontfile delete option also takes one file name as argument. It
deletes this file name from the list of encapsulated files.
The postscript terminal understands some font file formats: Type 1 fonts in ASCII file format (extension
".pfa"), Type 1 fonts in binary file format (extension ".pfb"), and TrueType fonts (extension ".ttf").
Pfa files are understood directly, pfb and ttf files are converted on the fly if appropriate conversion tools
are installed (see below). You have to specify the full filename with the extension. Each fontfile option
takes exact one font file name. This option can be used multiple times in order to include more than
one font file.
The font file is searched in the working directory and in all directories listed in the fontpath which
is determined by set fontpath. In addition, the fontpath can be set using the environment variable
GNUPLOT FONTPATH. If this is not set a system dependent default search list is used. See set
fontpath (p. 65) for more details.
For using the encapsulated font file you have to specify the font name (which normally is not the same
as the file name). When embedding a font file by using the fontfile option in interactive mode, the font
name is printed on the screen. E.g.
Font file ’p052004l.pfb’ contains the font ’URWPalladioL-Bold’. Location:
/usr/lib/X11/fonts/URW/p052004l.pfb
When using pfa or pfb fonts, you can also find it out by looking into the font file. There is a line similar
to "/FontName /URWPalladioL-Bold def". The middle string without the slash is the fontname, here
"URWPalladioL-Bold". For TrueType fonts, this is not so easy since the font name is stored in a binary
format. In addition, they often have spaces in the font names which is not supported by Type 1 fonts
(in which a TrueType is converted on the fly). The font names are changed in order to eliminate the
spaces in the fontnames. The easiest way to find out which font name is generated for use with gnuplot,
start gnuplot in interactive mode and type in "set terminal postscript fontfile ’’".
For converting font files to pfa format the conversion tool has to read the font from a file and write it
to standard output. For pfb files "pfbtops" is a tool which can do this. If this program is installed on
your system the on the fly conversion should work. Just try to encapsulate a pfb file. If the compiled