set terminal postscript eps enhanced color
set output "vwalker400.eps"
set contour
set isosamples 100
set cntrparam bspline
set cntrparam order 10
set cntrparam levels 15
set cntrparam levels incremental 0, 0.25
set view 0,0,1.5
set nosurface
set noclabel
set multiplot
splot [-1.5:1.5][-1.5:1.5](4*(1-x*x-y*y)*(1-x*x-y*y)+2*(x*x-2)*(x*x-2)+((x+y)*(x+y)-1)*((x+y)*(x+y)-1)+((x-y)*(x-y)-1)*((x-y)*(x-y)-1)-2)/6 notitle
set origin 0.018,0.075
set size 0.915,0.855
set data style vector
plot "simout.txt" notitle