A non-linear generalization of Ruhe & Wedin's algorithm
for separable non-linear least squares problem. It is implemented
as coordinate descent on an independent subset of the parameter
blocks at the end of every successful Newton step. The resulting
algorithm has much improved convergence at the cost of some
execution time.
Change-Id: I8fdc5edbd0ba1e702c9658b98041b2c2ae705402
more than just the residual block evaluation routines now.
Check the step computed by the linear solver for finiteness, and terminate early
if it is not. This will prevent bugs where the solver continues to run after
encountering an nan.
Sameer Agarwal