Synopsis
Allow model parameters to be varied during a fit.
Syntax
thaw(*args)
Description
The arguments can be parameters or models, in which case all parameters of the model are thawed. If no arguments are given then nothing is changed.
Examples
Example 1
Ensure that the FWHM parameter of the line model (in this case a `gauss1d` model) will be varied in any fit.
>>> set_source(const1d.bgnd + gauss1d.line) >>> thaw(line.fwhm) >>> fit()
Example 2
Thaw all parameters of the line model and then re-fit:
>>> thaw(line) >>> fit()
Example 3
Thaw the nh parameter of the gal model and the abund parameter of the src model:
>>> thaw(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 thaw. |
Notes
The `freeze` function can be used to reverse this setting, so that parameters are "frozen" and so remain constant during a fit.
Certain parameters may be marked as "always frozen", in which case using the parameter in a call to `thaw` will raise an error. If the model is sent to `thaw` then the "always frozen" parameter will be skipped.
Bugs
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.