Hello

Thank you so much for the opportunity to use the SimPEG and ask questions!

In the plot_fwd_nsem_MTTipper3D example,

problem = NSEM.Simulation3DPrimarySecondary( M, survey=survey, solver=Solver, sigma=sig, sigmaPrimary=sigBG)

I’m going to do some inversion,so i add the ‘sigmaMap=mapping’,

mapping = maps.InjectActiveCells(M, active_inds, sigma_air) * maps.ExpMap(ind_active.sum() )

problem1 = NSEM.Simulation3DPrimarySecondary( M, survey=survey, solver=Solver, sigma=sig, sigmaMap=mapping,sigmaPrimary=sigBG)

however the result of problem.dpred( ) != problem1.dpred(m_true)

I’ve checked that the sig == mapping*m_true

How can I get the right data?

Could you please help me?

Thank you in advance!