# set terminal svg size 600,400 dynamic enhanced fname 'arial'  fsize 10 mousing name "hidden_3" butt solid 
# set output 'hidden.3.svg'
set view 70, 45, 1, 1
set samples 20, 20
set isosamples 20, 20
set hidden3d back offset 1 trianglepattern 3 undefined 1 altdiagonal bentover
set title "Hidden line removal of explicit surfaces" 
set xrange [ -3.00000 : 3.00000 ] noreverse nowriteback
set yrange [ -3.00000 : 3.00000 ] noreverse nowriteback
splot sin(x*x + y*y) / (x*x + y*y)