Model fitting by least squares

Estimating the inverse gradient

To optimize the fitting goal (90), module unwrap() uses the conjugate-direction method like the modules cgmeth() and invstack(): user/gee/unwrap.c

    sf_igrad2_init(n1,n2);
    sf_tinysolver(sf_igrad2_lop,sf_cgstep,
		  n1*n2,n1*n2*2,hh,NULL,rt[0][0],niter);

An open question is whether or not the required number of iterations is reasonable or if we need to uncover a preconditioner or more rapid solution method. I adjusted the frame size (by the amount of smoothing in Figure 12) so that I would get the solution in about ten seconds with 400 iterations. Results are shown in Figure 13.

veshigh
Figure 13. Estimated altitude.

Revise igrad2 to make a module called tgrad2 which has transient boundaries.

synmod
Figure 14. Synthetic mountain with hidden backside. For your estimation enjoyment.

Model fitting by least squares