This man page is intended as a supplement to the command-line help provided by plt itself (using the -h option, see below). If you have not previously used plt, please look at the plt Tutorial and Cookbook, which is included in the plt package (see SOURCES below).
plt is a non-interactive (command line-driven) plotting utility. plt can produce publication-quality 2D plots in PostScript from easily-produced text or binary data files, and can also create screen plots under the X Window System.
All data presented to plt must be organized in rows and columns. Columns are numbered beginning with zero, and each column contains values for a variable that can be used as an abscissa (x coordinate), ordinate (y coordinate), or (with appropriate options described below) a grey level, color, or other plot attributes. Rows are numbered beginning with one, and each row contains a value for each column. Within a data-file, values are always arranged in row-major order (all elements of row 1, followed by all elements of row 2, etc.).
Usually, data must be in text form in order for plt to read them. Each non-empty, non-comment line (row) in the input should contain a value for each column that will be plotted; any additional values or other extra text at the end of a row will be ignored. Columns can be separated by any number of spaces or tabs. Commas and single or double quotation marks can also be used as column separators with current versions of plt, though not with older versions. It is not necessary to line up the values in each row. There may also be spaces or tabs at the beginning of a line, and these will also be ignored.
If no data-file is specified, plt reads data from its standard input. The command-line arguments xcol and ycol specify the column numbers for the abscissas and ordinates respectively. If only one column number is specified, it is taken as ycol, and plt generates a series of abscissas automatically. If the data-file contains no more than two columns, both xcol and ycol may be omitted.
By default, plt reads all rows of the data-file and scales the x and y axes so that all data can be plotted. An optional data-spec, a string beginning with a colon (:), can be used to select a subset of the rows in the data-file. For details on using a data-spec, and for information about reading binary data files using plt, see the plt Tutorial and Cookbook.
plt recognizes a large number of options for controlling and customizing plots. To see a summary of all options, run ``plt -h''; if this command is followed by one or more strings (which should not begin with hyphens), plt prints one-line summaries of all options beginning with those strings only.
can read its options from command-line arguments, from a format file (specified
using the -f option), or from a format string (supplied on the command line,
following the -F option). When using format files or format strings, omit
the hyphen (-) before each option.