Synopsis
Fix model parameters so they are not changed by a fit.
Syntax
freeze(*args)
Description
The arguments can be parameters or models, in which case all parameters of the model are frozen. If no arguments are given then nothing is changed.
Examples
Example 1
Fix the FWHM parameter of the line model (in this case a `gauss1d` model) so that it will not be varied in the fit.
>>> set_source(const1d.bgnd + gauss1d.line) >>> line.fwhm = 2.1 >>> freeze(line.fwhm) >>> fit()
Example 2
Freeze all parameters of the line model and then re-fit:
>>> freeze(line) >>> fit()
Example 3
Freeze the nh parameter of the gal model and the abund parameter of the src model:
>>> freeze(gal.nh, src.abund)
PARAMETERS
The parameter for this function is:
| Parameter | Type information | Definition |
|---|---|---|
| args | sequence of str or Parameter or Model | The parameters or models to freeze. |
Notes
The `thaw` function can be used to reverse this setting, so that parameters can be varied in a fit.
Bugs
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.