#### 3.15.6 functions

Built-in or user-defined functions can be displayed by the ‘plot‘ and ‘splot‘ commands in addition to, or instead of, data read from a file. The requested function is evaluated by sampling at regular intervals spanning the independent axis range[s]. See samples and isosamples. Example:

          approx(ang) = ang - ang**3 / (3*2)
          plot sin(x) title "sin(x)", approx(x) title "approximation"

To set a default plot style for functions, see ‘set style function‘. For information on built-in functions, see functions. For information on defining your own functions, see ‘user-defined‘.