4.1.0.45 mp

The ‘mp‘ driver produces output intended to be input to the Metapost program. Running Metapost on the file creates EPS files containing the plots. By default, Metapost passes all text through TeX. This has the advantage of allowing essentially any TeX symbols in titles and labels.

Syntax:

   set term mp {color | colour | monochrome}
               {solid | dashed}
               {notex | tex | latex}
               {magnification <magsize>}
               {psnfss | psnfss-version7 | nopsnfss}
               {prologues <value>}
               {a4paper}
               {amstex}
               {"<fontname>"} {<fontsize>}

The option ‘color‘ causes lines to be drawn in color (on a printer or display that supports it), ‘monochrome‘ (or nothing) selects black lines. The option ‘solid‘ draws solid lines, while ‘dashed‘ (or nothing) selects lines with different patterns of dashes. If ‘solid‘ is selected but ‘color‘ is not, nearly all lines will be identical. This may occasionally be useful, so it is allowed.

The option ‘notex‘ bypasses TeX entirely, therefore no TeX code can be used in labels under this option. This is intended for use on old plot files or files that make frequent use of common characters like ‘$‘ and ‘%‘ that require special handling in TeX.

The option ‘tex‘ sets the terminal to output its text for TeX to process.

The option ‘latex‘ sets the terminal to output its text for processing by LaTeX. This allows things like \\frac for fractions which LaTeX knows about but TeX does not. Note that you must set the environment variable TEX to the name of your LaTeX executable (normally latex) if you use this option or use ‘mpost –tex=<name of LaTeX executable> ...‘. Otherwise metapost will try and use TeX to process the text and it won’t work.

Changing font sizes in TeX has no effect on the size of mathematics, and there is no foolproof way to make such a change, except by globally setting a magnification factor. This is the purpose of the ‘magnification‘ option. It must be followed by a scaling factor. All text (NOT the graphs) will be scaled by this factor. Use this if you have math that you want at some size other than the default 10pt. Unfortunately, all math will be the same size, but see the discussion below on editing the MP output. ‘mag‘ will also work under ‘notex‘ but there seems no point in using it as the font size option (below) works as well.

The option ‘psnfss‘ uses postscript fonts in combination with LaTeX. Since this option only makes sense, if LaTeX is being used, the ‘latex‘ option is selected automatically. This option includes the following packages for LaTeX: inputenc(latin1), fontenc(T1), mathptmx, helvet(scaled=09.2), courier, latexsym and textcomp.

The option ‘psnfss-version7‘ uses also postscript fonts in LaTeX (option ‘latex‘ is also automatically selected), but uses the following packages with LaTeX: inputenc(latin1), fontenc(T1), times, mathptmx, helvet and courier.

The option ‘nopsnfss‘ is the default and uses the standard font (cmr10 if not otherwise specified).

The option ‘prologues‘ takes a value as an additional argument and adds the line ‘prologues:=<value>‘ to the metapost file. If a value of ‘2‘ is specified metapost uses postscript fonts to generate the eps-file, so that the result can be viewed using e.g. ghostscript. Normally the output of metapost uses TeX fonts and therefore has to be included in a (La)TeX file before you can look at it.

The option ‘noprologues‘ is the default. No additional line specifying the prologue will be added.

The option ‘a4paper‘ adds a ‘[a4paper]‘ to the documentclass. Normally letter paper is used (default). Since this option is only used in case of LaTeX, the ‘latex‘ option is selected automatically.

The option ‘amstex‘ automatically selects the ‘latex‘ option and includes the following LaTeX packages: amsfonts, amsmath(intlimits). By default these packages are not included.

A name in quotes selects the font that will be used when no explicit font is given in a ‘set label‘ or title. A name recognized by TeX (a TFM file exists) must be used. The default is "cmr10" unless ‘notex‘ is selected, then it is "pcrr8r" (Courier). Even under ‘notex‘, a TFM file is needed by Metapost. The file ‘pcrr8r.tfm‘ is the name given to Courier in LaTeX’s psnfss package. If you change the font from the ‘notex‘ default, choose a font that matches the ASCII encoding at least in the range 32-126. ‘cmtt10‘ almost works, but it has a nonblank character in position 32 (space).

The size can be any number between 5.0 and 99.99. If it is omitted, 10.0 is used. It is advisable to use ‘magstep‘ sizes: 10 times an integer or half-integer power of 1.2, rounded to two decimals, because those are the most available sizes of fonts in TeX systems.

All the options are optional. If font information is given, it must be at the end, with size (if present) last. The size is needed to select a size for the font, even if the font name includes size information. For example, ‘set term mp "cmtt12"‘ selects cmtt12 shrunk to the default size 10. This is probably not what you want or you would have used cmtt10.

The following common ascii characters need special treatment in TeX:

   $, &, #, %, _;  |, <, >;  ^, ~,  \\, {, and }

The five characters $, #, &, _, and % can simply be escaped, e.g., ‘\\$‘. The three characters <, >, and | can be wrapped in math mode, e.g., ‘$<$‘. The remainder require some TeX work-arounds. Any good book on TeX will give some guidance.

If you type your labels inside double quotes, backslashes in TeX code need to be escaped (doubled). Using single quotes will avoid having to do this, but then you cannot use ‘\\n‘ for line breaks. As of this writing, version 3.7 of gnuplot processes titles given in a ‘plot‘ command differently than in other places, and backslashes in TeX commands need to be doubled regardless of the style of quotes.

Metapost pictures are typically used in TeX documents. Metapost deals with fonts pretty much the same way TeX does, which is different from most other document preparation programs. If the picture is included in a LaTeX document using the graphics package, or in a plainTeX document via epsf.tex, and then converted to PostScript with dvips (or other dvi-to-ps converter), the text in the plot will usually be handled correctly. However, the text may not appear if you send the Metapost output as-is to a PostScript interpreter.

— METAPOST INSTRUCTIONS —

- Set your terminal to Metapost, e.g.:

   set terminal mp mono "cmtt12" 12

- Select an output-file, e.g.:

   set output "figure.mp"

- Create your pictures. Each plot (or multiplot group) will generate a separate Metapost beginfig...endfig group. Its default size will be 5 by 3 inches. You can change the size by saying ‘set size 0.5,0.5‘ or whatever fraction of the default size you want to have.

- Quit gnuplot.

- Generate EPS files by running Metapost on the output of gnuplot:

   mpost figure.mp  OR  mp figure.mp

The name of the Metapost program depends on the system, typically ‘mpost‘ for a Unix machine and ‘mp‘ on many others. Metapost will generate one EPS file for each picture.

- To include your pictures in your document you can use the graphics package in LaTeX or epsf.tex in plainTeX:

   \\usepackage{graphics} % LaTeX
   \\input epsf.tex       % plainTeX

If you use a driver other than dvips for converting TeX DVI output to PS, you may need to add the following line in your LaTeX document:

   \\DeclareGraphicsRule{*}{eps}{*}{}

Each picture you made is in a separate file. The first picture is in, e.g., figure.0, the second in figure.1, and so on.... To place the third picture in your document, for example, all you have to do is:

   \\includegraphics{figure.2} % LaTeX
   \\epsfbox{figure.2}         % plainTeX

The advantage, if any, of the mp terminal over a postscript terminal is editable output. Considerable effort went into making this output as clean as possible. For those knowledgeable in the Metapost language, the default line types and colors can be changed by editing the arrays ‘lt[]‘ and ‘col[]‘. The choice of solid vs dashed lines, and color vs black lines can be change by changing the values assigned to the booleans ‘dashedlines‘ and ‘colorlines‘. If the default ‘tex‘ option was in effect, global changes to the text of labels can be achieved by editing the ‘vebatimtex...etex‘ block. In particular, a LaTeX preamble can be added if desired, and then LaTeX’s built-in size changing commands can be used for maximum flexibility. Be sure to set the appropriate MP configuration variable to force Metapost to run LaTeX instead of plainTeX."