> xeasy
> 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
>  
> Contour plot         [cp]
>  
> level and bas 1 -3099.656738
> level and bas 2 -2214.183350
> level and bas 3 -1581.702393
> level and bas 4 -1129.930298
> level and bas 5 -807.235962
> level and bas 6 -576.739990
> level and bas 7 -412.100006
> level and bas 8 -294.500000
> level and bas 9 -210.500000
> level and bas 10 -150.500000
> level and bas 11 150.500000
> level and bas 12 210.500000
> level and bas 13 294.500000
> level and bas 14 412.100006
> level and bas 15 576.739990
> level and bas 16 807.235962
> level and bas 17 1129.930298
> level and bas 18 1581.702393
> level and bas 19 2214.183350
> level and bas 20 3099.656738
>  
> Contour plot         [cp]
>  
> level and bas 1 -2066.604492
> level and bas 2 -1476.288940
> level and bas 3 -1054.635010
> level and bas 4 -753.453552
> level and bas 5 -538.323975
> level and bas 6 -384.659973
> level and bas 7 -274.899994
> level and bas 8 -196.500000
> level and bas 9 -140.500000
> level and bas 10 -100.500000
> level and bas 11 100.500000
> level and bas 12 140.500000
> level and bas 13 196.500000
> level and bas 14 274.899994
> level and bas 15 384.659973
> level and bas 16 538.323975
> level and bas 17 753.453552
> level and bas 18 1054.635010
> level and bas 19 1476.288940
> level and bas 20 2066.604492
>