Synopsis
Set the optimization method
Syntax
set_method( meth )
Description
The set_method command sets the optimization method to be used in fitting.
- meth - the optimization method
Available methods are returned by the list_methods command ("ahelp list_methods"). There is a help file for each method, e.g. ("ahelp levmar").
Method | Description |
---|---|
levmar | The Levenberg-Marquardt method is an interface to the MINPACK subroutine lmdif to find the local minimum of nonlinear least squares functions of several variables by a modification of the Levenberg-Marquardt algorithm (J.J. More, "The Levenberg Marquardt algorithm: implementation and theory," in Lecture Notes in Mathematics 630: Numerical Analysis, G.A. Watson (Ed.), Springer-Verlag: Berlin, 1978, pp.105-116). |
moncar | The implementation of the moncar method is based on the paper by Storn, R. and Price, K. "Differential Evolution: A Simple and Efficient Adaptive Scheme for Global Optimization over Continuous Spaces." J. Global Optimization 11, 341-359, 1997. |
neldermead | The implementation of the Nelder Mead Simplex direct search is based on the paper: Jeffrey C. Lagarias, James A. Reeds, Margaret H. Wright, Paul E. Wright "Convergence Properties of the Nelder-Mead Simplex Algorithm in Low Dimensions", SIAM Journal on Optimization,Vol. 9, No. 1 (1998), pages 112-147. |
simplex | same as the neldermead method |
Examples
Example 1
sherpa> set_method("neldermead")
Set the optimization method as the Nelder Mead simplex.
Example 2
sherpa> set_method("moncar")
The optimization method is set to "moncar".
Bugs
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.
See Also
- confidence
- set_conf_opt, set_covar_opt, set_proj_opt
- data
- set_areascal, set_arf, set_backscal, set_bkg, set_coord, set_counts, set_data, set_exposure, set_grouping, set_quality, set_rmf, set_staterror, set_syserror
- filtering
- set_filter
- methods
- gridsearch, levmar, list_iter_methods, list_methods, moncar, neldermead, set_iter_method, set_iter_method_opt, set_method_opt
- modeling
- get_par, set_bkg_model, set_full_model, set_par, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxsect, set_xsxset
- statistics
- set_prior, set_sampler, set_sampler_opt, set_stat
- utilities
- set_analysis, set_default_id
- visualization
- image_setregion