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PARAMETERS extension

There will be a BINTABLE extension called PARAMETERS containing the parameter definitions and tabulated values. The header keywords will be :

  1. NINTPARM - the number of interpolated parameters (integer).
  2. NADDPARM - the number of additional parameters (integer).

and the columns will be :


NAME 		 12A 		 name of the parameter.

METHOD J interpolation method (0 if linear, 1 if logarithmic)
INITIAL E initial value in the fit for the parameter
DELTA E parameter delta used in fit (if negative parameter is frozen)
MINIMUM E hard lower limit for parameter value
BOTTOM E soft lower limit for parameter value
TOP E soft upper limit for parameter value
MAXIMUM E hard upper limit for parameter value
NUMBVALS J the number of tabulated parameter values
VALUE nE the tabulated parameter values (n is NUMBVALS)

Neither METHOD or VALUE are set for the additional parameters. The six numbers in the INITIAL vector are the start, delta, low, bottom, top, and high parameter values. The tabulated parameter values must be stored in VALUE in increasing order.

This extension should also include the standard OGIP keywords :


HDUCLASS 		 'OGIP'           

HDUCLAS1 'XSPEC TABLE MODEL'
HDUCLAS2 'PARAMETERS'
HDUVERS '1.0.0'


next up previous
Next: ENERGIES extension Up: The FITS file format Previous: Primary header
Keith Arnaud
2005-05-10