3.11 Directing where output goes
By default, when Pyxplot is used interactively, all plots are displayed on the screen. It is also possible to produce PostScript output, to be read into other programs or embedded into latex documents, as well as a variety of other graphical formats such as jpeg and png. The set terminal command1 is used to specify the output format that is required, and the set output command is used to specify the file to which output should be directed. For example,
set terminal pdf set output 'myplot.pdf' plot 'datafile.dat'
would output a PDF plot of data from the file datafile.dat to the file myplot.pdf, which could be opened in Adobe Reader.
The set terminal command can also be used to configure various output options within each supported file format. For example, the following commands would produce black-and-white or color output respectively:
set terminal monochrome set terminal color
The former is useful for preparing plots for black-and-white publications, the latter for preparing plots for colorful presentations.
Both PostScript and Encapsulated PostScript can be produced. The former is recommended for producing figures to embed into documents, the latter for plots which are to be printed without further processing. The postscript terminal produces the latter; the eps terminal should be used to produce the former. Similarly the pdf terminal produces files in the Portable Document Format (PDF) read by Adobe Acrobat:
set terminal postscript set terminal eps set terminal pdf
It is also possible to produce plots in the gif, png and jpeg graphic formats, as follows:
set terminal gif set terminal png set terminal jpg
More than one of the above keywords can be combined on a single line, for example:
set terminal postscript color set terminal gif monochrome
To return to the default state of displaying plots on screen, the x11 terminal should be selected:
set terminal x11
After changing terminals, the refresh command2 is especially useful; it reproduces the last plot to have been generated in the newly-selected graphical format. For more details of the set terminal command, including how to produce gif and png images with transparent backgrounds, see Chapter 9.