Copyright (C) 1996 The Regents of the University of California, All
Rights Reserved. Written by Matthew W. Craig.

PURPOSE:
The purpose of the TeXtoIDL routines is to make it simple to use Greek
letters, subscripts and superscripts in making labels for plots in
IDL. This is accomplished by allowing the user to use TeX control
sequences for Greek letters and special symbols and for
sub/superscripts. The TeX control sequences are simple and easy to
remember, especially if you already use TeX for writing papers (for
those unfamiliar with TeX, an explanation of that notation is below).
The translation is done for either vector or PostScript fonts.

BUGS:
Please report any bugs you find or suggestions for improvement to:
mcraig@mnstate.edu

FILES:
For a list of the files in this distribution see the file FILES.
For a list of one line descriptions of the routines in this
distribution, see the file DESCRIPTIONS.

INSTALLATION:
Put these routines somewhere in you IDL path.

USE:
Once installed, type (in IDL):
IDL> print,TeXtoIDL(/HELP)
for brief instructions. The command SHOWTeX will display the
available TeX sequences on the current graphics device. In addition,
subscripts and superscripts in the usual TeX notation are available.
For more details on what TeX notation is, see the section
INTRO TO TeX, below.

EXAMPLE:
If you type. . .
IDL> str = TeXtoIDL("\rho^2 + 2\Gamma_{ij}")
IDL> help, str
STR STRING = '!7q!X!U2!N + 2!7C!X!Dij!N'
IDL> xyouts,.5,.5,str,CHARSIZE=2.,/NORM

then on the screen you will see the Greek letter rho with a 2 in the
exponent, and then a + and then a 2 and then the uppercase Greek
letter gamma, with an "ij" in the subscript.

VERSION:
You are using version $Name: Rel_2_1_2 $ of TeXtoIDL.

REVISION HISTORY:
See the file VERSIONS.

LEGALITIES:
For copyright and redistribution restrictions, see the file
COPYRIGHT.

This software is provided on an "as is" basis, and has absolutely
NO warranty. For more details, see the file DISCLAIMER.

INTRO TO TeX:
TeX is a typesetting language which makes including equations in
manuscripts very easy. In particular, it has an easy to remember
syntax for including Greek letters, special symbols, and subscripts
and superscripts. These routines emulate the behavior of TeX,
allowing its syntax to be used in making IDL plot labels and the
like.

The TeX syntax for Greek letters is simple. If you want, for
example, the Greek letter "rho", just type "\rho" and you will get it.
The IDL string for "rho" is "!7q!X" (for vector fonts) or "!Mr!X" (for
PostScript fonts). In any event, the IDL strings are not easy to
remember, and depend on the font type. If you type SHOWTEX at the IDL
command line, a table will be made on the current graphics device
showing which Greek letters and special symbols are available, and
what they look like on your graphics device.

The syntax for sub/superscripts is also simple. An example will make
it clear. If I write "N_{sub}", I will get an "N" with the subscript
"sub". The underscore begins the subscript, and everything enclosed
in the braces is in the subscript. Superscripts are similar;
"N^{sup}" is an "N" with a superscript "sup". Since it is frequent to
have one character sub- or superscripts, braces are not needed for a
one character script. So "N^2" makes an "N" with a "2" in the
exponent. You can combine sub and superscripts, for example
"N^2_{sub}", and you can even put subscripts on the things in your
superscripts, e.g. "N^{N_j}", though this probably won't look very
good.