recorn: change correction norm for a spectrum
This model is a replacement for and improvement on the old xspec command
recornrm. If a correction file is in use for a spectrum then its normalization
can be fitted for using this model. The first parameter, which is not
variable, is the spectrum number and the second the correction file
normalization. The starting value of the second parameter should be set to
the current value of the correction file norm (this can be independently
set using the cornorm command).
Note that in order to fit the cornorm parameter the calculation of
parameter derivatives during the fit must be switched to the slower
full numerical differentiation algorithm. This can be done either by
XSPEC12>xset usechainrule no
or by changing the USE_CHAIN_RULE setting in the Xspec.init start-up file
to false. This does slow down the fit so is not recommended
for general use.
par1 |
specnum: spectrum number |
par2 |
cornorm: correction file normalization |
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Last modified: Friday, 23-Aug-2024 13:20:40 EDT
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