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Last modified: December 2013

URL: http://cxc.harvard.edu/sherpa/ahelp/freeze.html
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AHELP for CIAO 4.9 Sherpa v1

freeze

Context: modeling

Synopsis

Freeze model parameters, so they do not vary during a fit.

Syntax

freeze([parameter], [[parameters]])

Description

Given one or more model parameters, freeze each model parameter at its current value. The frozen parameters are not varied during a fit. (If an argument is a model, then all the model parameters of that model are frozen.)

  • parameter(s) - model parameters to freeze for the fit

One of more model parameters may be specified as a comma-separated list. If the model name is provided without a parameter specified, all of the parameters in the model are frozen.

To unfreeze model parameter values and allow them to vary, the command thaw ("ahelp thaw") is used.

Example 1

sherpa> freeze(g.ampl)

The model parameter "ampl" of model "g" is frozen at its current value.

Example 2

sherpa> freeze(g.ampl, g.fwhm)

Both model parameters "ampl" and "fwhm" of model "g" are frozen at their current values.

Example 3

sherpa> freeze(g)

All model parameters specified in model "g" are frozen at their current values.

Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

contrib
renorm
modeling
guess, link, paramprompt, set_par, thaw, unlink

Last modified: December 2013
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