next up previous contents
Next: ftest Up: Fit Commands Previous: fit

            freeze: set parameters as fixed

Do not allow indicated model parameters to vary. (See also thaw.)

Syntax:           freeze [ <param range>...]

where

<param range =:: [modelName:] <param#> | <param#> — <param#>.

The indicated model parameter or range of model parameters will be marked so they cannot be varied by the fit command. By default,the range will be the last range input by either a freeze or thaw command.

Examples:

Currently there are six parameters, initially all unfrozen.

 

XSPEC12> freeze 2

//Parameter 2 is frozen

XSPEC12> freeze 4-6

//Parameters 4, 5, and 6 are frozen.

XSPEC12> thaw 2 3-5

//Parameters 2, 4, and 5 are thawed, parameter 3 is unaffected.

XSPEC12> freeze

//Parameters 3,4,5 are frozen (the last range input by a freeze

//or thaw command).