The set spiderplot command switches interpretation of coordinates to a
polar system in which each data point is mapped to a position along a
radial axis. paxis 1 is always vertical; axes 2 to N proceed clockwise
with even spacing. The command must be issued prior to plotting. It has
additional effects equivalent to
set style data spiderplot
unset border
unset tics
set key noautotitle
set size ratio 1.0
Use reset to restore these after plotting.
