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Last modified: December 2013

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

thaw

Context: modeling

Synopsis

Thaw model parameters so they vary during a fit

Syntax

thaw([parameter])

Description

The thaw command thaws the specified model parameters so that they may vary during a fit.

  • parameter(s) - parameters to thaw

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 thawed.

To fix a parameter at the current value during a fit, use the freeze command ("ahelp freeze").

Example 1

sherpa> thaw(pl.ampl)

Thaw the amplitude parameter of a powerlaw1d model named "pl".

Example 2

sherpa> set_source(xswabs.gal*xsmekal.mek)
sherpa> thaw(mek.kT)

Create a source model and thaw the plasma temperature parameter (kt) of the xsmekal model.

Example 3

sherpa> thaw(poly.c1, poly.c2)

Thaw the second and third (c1, c2) coefficients of a polynomial model.

Example 4

sherpa> thaw(poly)

Thaw all of the components of the polynomial model.

Bugs

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

See Also

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

Last modified: December 2013
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