set_iter_method_opt¶
-
sherpa.astro.ui.
set_iter_method_opt
(optname, val)¶ Set an option for the iterative-fitting scheme.
- Parameters
optname (str) – The name of the option to set. The get_iter_method_opt routine can be used to find out valid values for this argument.
val – The new value for the option.
- Raises
sherpa.utils.err.ArgumentErr – If the
optname
argument is not recognized.
See also
get_iter_method_name()
Return the name of the iterative fitting scheme.
get_iter_method_opt()
Return one or all options for the iterative-fitting scheme.
list_iter_methods()
List the iterative fitting schemes.
set_iter_method()
Set the iterative-fitting scheme used in the fit.
Notes
The supported fields for the
primini
scheme are:- maxiters
The maximum number of iterations to perform.
- tol
The iteration stops when the change in the best-fit statistic varies by less than this value.
The supported fields for the
sigmarej
scheme are:- grow
The number of points adjacent to a rejected point that should also be removed. A value of
0
means that only the discrepant point is removed whereas a value of1
means that the two adjacent points (one lower and one higher) will also be removed.- hrej
The rejection criterion in units of sigma, for data points above the model (it must be >= 0).
- lrej
The rejection criterion in units of sigma, for data points below the model (it must be >= 0).
- maxiters
The maximum number of iterations to perform. If this value is
0
then the fit will run until it has converged.
Examples
Reject any points that are more than 5 sigma away from the best fit model and re-fit.
>>> set_iter_method('sigmarej') >>> set_iter_method_opt('lrej', 5) >>> set_iter_method_opt('hrej', 5) >>> fit()