The sampling rate of functions, or for interpolating data, may be changed by the samples command.
Syntax:
set samples <samples_1> {,<samples_2>}
show samples
By default, sampling is set to 100 points. A higher sampling rate will produce more accurate plots, but will take longer. This parameter has no effect on data file plotting unless one of the interpolation/approximation options is used. See smooth re 2D data and cntrparam and dgrid3d re 3D data.
When a 2D graph is being done, only the value of <samples_1> is relevant.
When a surface plot is being done without the removal of hidden lines, the value of samples specifies the number of samples that are to be evaluated for the isolines. Each iso-v line will have <sample_1> samples and each iso-u line will have <sample_2> samples. If you only specify <samples_1>, <samples_2> will be set to the same value as <samples_1>. See also isosamples.