> xeasy
> Contour plot         [cp]
>  
> level and bas 1 -0.500000
> level and bas 2 -0.500000
> level and bas 3 -0.500000
> level and bas 4 -0.500000
> level and bas 5 -0.500000
> level and bas 6 -0.500000
> level and bas 7 -0.500000
> level and bas 8 -0.500000
> level and bas 9 -0.500000
> level and bas 10 -0.500000
> level and bas 11 0.500000
> level and bas 12 0.500000
> level and bas 13 0.500000
> level and bas 14 0.500000
> level and bas 15 0.500000
> level and bas 16 0.500000
> level and bas 17 0.500000
> level and bas 18 0.500000
> level and bas 19 0.500000
> level and bas 20 0.500000
>  
> Contour plot         [cp]
>  
> level and bas 1 -8264.917969
> level and bas 2 -5903.655762
> level and bas 3 -4217.040039
> level and bas 4 -3012.314209
> level and bas 5 -2151.795898
> level and bas 6 -1537.139893
> level and bas 7 -1098.099976
> level and bas 8 -784.500000
> level and bas 9 -560.500000
> level and bas 10 -400.500000
> level and bas 11 400.500000
> level and bas 12 560.500000
> level and bas 13 784.500000
> level and bas 14 1098.099976
> level and bas 15 1537.139893
> level and bas 16 2151.795898
> level and bas 17 3012.314209
> level and bas 18 4217.040039
> level and bas 19 5903.655762
> level and bas 20 8264.917969
>