Rrange

For a polar plot, the radial co-ordinate should be non-negative, but rrange can be used to move the singularity.

Syntax:

        set rrange {[<rmin>:<rmax>]}
        show rrange

rmin specifies the radius at the origin and rmax provides clipping for large radii. xrange and yrange are affected—the ranges can be set as if the plot was of r(t)-rmin, with rmin added to all the labels. (set term table reveals that it is in fact implemented that way.)