The  set rrange command sets the radial range used to compute x and y
 values when in polar mode. If not in polar mode (see  set polar) then
 this range is not used. Use of this command offsets the polar
 singularity to the  value and shifts the units on the axes tic
 marks. For instance, set rrange [-40:40] would set the origin to -40
 and would plot values of radial values between -40 to 40. Thus, if
 360 degrees of data were plotted, then the plot would extend 80 units
 in radially from the origin.  To view the entire plot,  a
 set yrange [-80:80] command would create a square viewport with
 a circular plot tangent at the axes.  Because  xrange is used
 specify the angular extent, only a square viewport can be specified
 by  yrange.  For instance, set yrange [0:80] would display the
 first quadrant and set yrange [-80:0] would display the third
 quadrant.  Any square viewport of any size can be specified but it
 is constrained to be centered on a 45 degree line.

 This range may also be specified on the  plot command line when in
 polar mode.

 Syntax:
         set rrange [{ : }]

 where  and  terms are constants or expressions.

 Both the  and  terms are optional. Anything omitted will
 not be changed, so
         set rrange [:10]
 changes rmax to 10 without affecting rmin.