- sherpa.astro.ui.save_delchi(id, filename=None, bkg_id=None, ascii=True, clobber=False)
Save the ratio of residuals (data-model) to error to a file.
id (int or str, optional) – The identifier for the data set to use. If not given then the default identifier is used, as returned by
filename (str) – The name of the file to write the array to. The format is determined by the
bkg_id (int or str, optional) – Set if the background residuals should be written out rather than the source.
ascii (bool, optional) – If
Falsethen the data is written as a FITS format binary table. The default is
True. The exact format of the output file depends on the I/O library in use (Crates or AstroPy).
clobber (bool, optional) – If
None, then this flag controls whether an existing file can be overwritten (
True) or if it raises an exception (
False, the default setting).
sherpa.utils.err.IdentifierErr – If no model has been set for this data set.
sherpa.utils.err.IOErr – If
filenamealready exists and
Save the data to a file.
Save the residuals (data-model) to a file.
The function does not follow the normal Python standards for parameter use, since it is designed for easy interactive use. When called with a single un-named argument, it is taken to be the
filenameparameter. If given two un-named arguments, then they are interpreted as the
filenameparameters, respectively. The remaining parameters are expected to be given as named arguments.
The output file contains the columns
DELCHI. The residuals array respects any filter or (for PHA files), grouping settings.
Write the residuals to the file “delchi.dat”:
Write the residuals from the data set ‘jet’ to the FITS file “delchi.fits”:
>>> save_delchi('jet', "delchi.fits", ascii=False)