sherpa.astro.ui.save_arf(id, filename=None, resp_id=None, bkg_id=None, ascii=False, clobber=False)

Save an ARF data set to a file.

Added in version 4.16.0.

  • id (int or str) – The identifier for the data set containing the ARF or the filename (the latter is used when filename is set to None, and in this case the id is set to the default identifier, as returned by get_default_id).

  • filename (str or None) – The name of the file to write the ARF to (when the id value is explicitly given). The format is determined by the ascii argument.

  • resp_id (int or str, optional) – The identifier for the ARF within this data set, if there are multiple responses.

  • bkg_id (int or str, optional) – Set if the background ARF should be written out rather than the source ARF.

  • ascii (bool, optional) – If False then the data is written as a FITS format binary table. The exact format of the output file depends on the I/O library in use (Crates or AstroPy).

  • clobber (bool, optional) – This flag controls whether an existing file can be overwritten (True) or if it raises an exception (False).



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 filename parameter. If given two un-named arguments, then they are interpreted as the id and filename parameters, respectively. The remaining parameters must be given as named arguments.


Write out the ARF data from the default data set to the file ‘src.arf’:

>>> save_arf('src.arf')

Over-write the file it it already exists, and take the data from the data set “jet”:

>>> save_arf('jet', 'out.arf', clobber=True)

Write the data out as an ASCII file:

>>> save_arf('pi.arf', ascii=True)