> xeasy
> Contour plot         [cp]
>  
> level and bas 1 -2066105.125000
> level and bas 2 -1475789.500000
> level and bas 3 -1054135.500000
> level and bas 4 -752954.062500
> level and bas 5 -537824.500000
> level and bas 6 -384160.500000
> level and bas 7 -274400.500000
> level and bas 8 -196000.500000
> level and bas 9 -140000.500000
> level and bas 10 -100000.500000
> level and bas 11 100000.500000
> level and bas 12 140000.500000
> level and bas 13 196000.500000
> level and bas 14 274400.500000
> level and bas 15 384160.500000
> level and bas 16 537824.500000
> level and bas 17 752954.062500
> level and bas 18 1054135.500000
> level and bas 19 1475789.500000
> level and bas 20 2066105.125000
>