set parametric
set pm3d 
set palette rgb 8,-4,23
unset key
set samples 200
set cbrange[-0.5:0.5]
set vrange[0:2*pi]
set urange[0:2*pi]
set size square
set view 40,30
set term png transparent xffffff
set out "flower2.png"
splot (0.3+0.7*cos(7*u))*cos(2*u),\
      (0.3+0.7*cos(7*u))*sin(2*u), \
      0.8*(0.3+0.7*cos(7*u))-0.18*(cos(21*u)-cos(7*u))-0.22 lw 3 palette
!convert -geometry 50% -colors 256 flower2.png flower2_s.png
!display flower2_s.png