Apply GN/LM methods for solve nonlinear least squares problems (local step) #18
Description
Currently, the NLP problems in local step are solved as a standard optimization, although the problem is formulated as a least-sqaures problem.
In order to gain more benefit from LS structure, i.e., saving computing time and increasing robustness, Gauss-Newton method and Levenberg Marquadt method will be implemented in rapidPF.