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Caveats: set_analysis
Caveats
Model evaluation is based on an energy grid even if
'set_analysis("wave")' has been issued.
Caveats
-
Model evaluation is based on an energy grid even if
'set_analysis("wave")' has been issued.
When Sherpa 4.1 evaluates a model for an input PHA data set,
model parameter values are computed using an energy grid, regardless
of whether the
'set_analysis("wavelength")'
command (S-Lang or Python help) has been issued. The model parameters are
always returned in units of keV (energy).
Workaround:
The translation between keV and Angstroms can be made by
calculating
λ(A)=hc/E(keV),
where 'hc' is a constant (Planck's constant times speed of
light) and λ is given in Angstroms.
If the data is binned, the size of the bins in keV, d(E),
translates to the size in Angstroms, d(λ), as
d(λ)= -d(E)*hc/E2.
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