2-D inversion program of R. Mackie, graphics program for postscript output by V. Rath.

Inversion of TE- and TM apparent resistivity and phase data from 22 sites, weight placed on phases

by increasing error floor for app. resistivity; start model: homogeneous halfspace, resistivity 20 Ohm.m

Animated gifs show iteration steps (1-30, regularisation parameter tau = 20) and an evolving conductor

below the Bolivian Altiplano. Resulting rms is mainly due to static shifts.

Gradient norm, rms = 3.6	Laplacian Norm, rms = 3.4