> xeasy
> Contour plot         [cp]
>  
> level and bas 1 -6198.812988
> level and bas 2 -4427.866699
> level and bas 3 -3162.904785
> level and bas 4 -2259.360596
> level and bas 5 -1613.971802
> level and bas 6 -1152.979980
> level and bas 7 -823.699951
> level and bas 8 -588.500000
> level and bas 9 -420.500000
> level and bas 10 -300.500000
> level and bas 11 300.500000
> level and bas 12 420.500000
> level and bas 13 588.500000
> level and bas 14 823.699951
> level and bas 15 1152.979980
> level and bas 16 1613.971802
> level and bas 17 2259.360596
> level and bas 18 3162.904785
> level and bas 19 4427.866699
> level and bas 20 6198.812988
>