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The Plotutils Package

A.3 Available text fonts for the X Window System

The command-line graphics programs graph -T X, plot -T X, pic2plot -T X, tek2plot -T X, and plotfont -T X, and the libplot library that they are built on, can draw text on an X Window System display in a wide variety of fonts. This includes the 22 built-in Hershey vector fonts. They can use the 35 built-in Postscript fonts too, if those fonts are available on the X display. Most releases of the plotting utilities include freely distributable versions of the 35 Postscript fonts, in Type 1 format, that are easily installed on any X display.

In fact, the plotting utilities can use most fonts that are available on the current X display. This includes all scalable fonts that have a so-called XLFD (X Logical Font Description) name. For example, the "CharterBT-Roman" font is available on many X displays. It has a formal XLFD name, namely "-bitstream-charter-medium-r-normal--0-0-0-0-p-0-iso8859-1". The plotting utilities would refer to it as "charter-medium-r-normal". The command

echo 0 0 1 1 2 0 | graph -T X -F charter-medium-r-normal

would draw a plot in a popped-up X window, in which all axis ticks are labeled in this font.

You may determine which fonts are available on an X display by using the xlsfonts command. Fonts whose names end in "-0-0-0-0-p-0-iso8859-1" or "-0-0-0-0-m-0-iso8859-1" are scalable ISO-Latin-1 fonts that can be used by libplot's X Plotters and by the plotting utilities that are built on libplot. The two sorts of font are variable-width and fixed-width fonts, respectively. Fonts whose names end in "iso8859-2", etc., and "adobe-fontspecific", may also be used, even though they do not employ the standard ISO-Latin-1 encoding.

The escape sequences that provide access to the non-ASCII `8-bit' characters in the built-in ISO-Latin-1 fonts may be employed when using any ISO-Latin-1 X Window System font. For more on escape sequences, see A.4 Text string format and escape sequences. As an example, "\Po" will yield the British pounds sterling symbol `£'. The command

echo 0 0 1 1 | graph -T X -F charter-medium-r-normal -L "A \Po1 Plot"

shows how this symbol could be used in a graph label. In the same way, the escape sequences that provide access to mathematical symbols and Greek characters may be employed when using any X Window System font, whether or not it is an ISO-Latin-1 font.

The plotting utilities, including graph, support a `--bitmap-size' option. If the `-T X' option is used, it sets the size of the popped-up X Window. You may use it to obtain some interesting visual effects. Each of the plotting utilities assumes that it is drawing in a square region, so if you use the `--bitmap-size 800x400' option, your plot will be scaled anisotropically, by a larger factor in the horizontal direction than in the vertical direction. The fonts in the plot will be scaled in the same way. Actually, this requires a modern (X11R6) display. If your X display cannot scale a font, a default scalable font (such as "HersheySerif") will be substituted.