### 12.2 Plotting Formats

Maxima can use either Gnuplot, Xmaxima or Geomview as graphics program. Gnuplot and Geomview are external programs which must be installed separately, while Xmaxima is distributed with Maxima. To see which plotting format you are currently using, use the command `get_plot_option(plot_format);` and to change to another format, you can use `set_plot_option([plot_format, <format>])`, where `<format>` is the name of one of the formats described below. Those two commands show and change the global plot format, while each individual plotting command can use its own format, if it includes an option `[plot_format, <format>]` (see `get_plot_option` and `set_plot_option`).

The plotting formats are the following:

- gnuplot (default on Windows)

  Used to launch the external program gnuplot, which must be installed in your system. All plotting commands and data are saved into the file `maxout_xxx.gnuplot`.

- gnuplot_pipes (default on non-Windows platforms)

  It is similar to the `gnuplot` format except that the commands and plot data are sent directly to `gnuplot` without creating any files. A single gnuplot process is kept open, with a single graphic window, and subsequent plot commands will be sent to the same process, replacing previous plots in that same window. Even if the graphic window is closed, the `gnuplot` process is still running until the end of the session or until it is killed with `gnuplot_close`.. The function `gnuplot_replot` can be used to modify a plot that has already been displayed on the screen or to open again the graphic window after it was closed.

  This format does not work with some versions of Lisp under Windows and it is only used to plot to the screen; whenever graphic files are to be created, the format is silently switched to `gnuplot` and the commands needed to create the graphic file are saved with the data in file `maxout_xxx.gnuplot`.

- mgnuplot

  Mgnuplot is a Tk-based wrapper around gnuplot. It is an old interface still included in the Maxima distribution, but it is currently disabled because it does not have most of the features introduced by the newer versions of the plotting commands. Mgnuplot requires an external gnuplot installation and, in Unix systems, the Tcl/Tk system.

- xmaxima

  Xmaxima is a Tcl/Tk graphical interface for Maxima that can also be used to display plots created when Maxima is run from the console or from other graphical interfaces. To use this format, the xmaxima program, which is distributed together with Maxima, must be installed; in some Linux distributions Xmaxima is distributed in a package separate from other parts of Maxima. If Maxima is being run from the Xmaxima console, the data and commands are passed to xmaxima through the same socket used for the communication between Maxima and the Xmaxima console. When used from a terminal or from graphical interfaces different from Xmaxima, the commands and data are saved in the file `maxout_xxx.xmaxima` and xmaxima is run with the name of that file as argument.

- geomview

  Geomview, a Motif based interactive 3D viewing program for Unix. It can only be used to display plots created with `plot3d`. To use this format, the geomview program must be installed.

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Categories: Plotting