A problem in linear_invert.jl example?

[zhang-rite]

Hi @kailaix

Thanks for the nice contribution. Could you check is there a problem in your showcase model linear_invert.jl? I find even without the extraction (i.e., let qo source be zero) there is always a negative potential and a shrinking displacement. In your recent CMAME paper, the positive deformation due to injection also seems invisible (Fig. 20 right).

Thanks!