save_syserror

sherpa.astro.ui.save_syserror(id, filename=None, bkg_id: IdType | None = None, ascii=True, clobber=False) → None

Save the systematic errors to a file.

Parameters:

idint or str, optional

The identifier for the data set to use. If not given then the default identifier is used, as returned by get_default_id.

filenamestr

The name of the file to write the array to. The format is determined by the ascii argument.

bkg_idint, str, or None, optional

Set if the background should be written out rather than the source.

asciibool, optional

If False then 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).

clobberbool, optional

If outfile is not None, then this flag controls whether an existing file can be overwritten (True) or if it raises an exception (False, the default setting).

Raises:

sherpa.utils.err.IOErr

If the data set does not contain any systematic errors.

sherpa.utils.err.DataErr

If filename already exists and clobber is False.

See also

load_syserror

Load the systematic errors from a file.

save_error

Save the errors to a file.

save_staterror

Save the statistical errors to a file.

Notes

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 are expected to be given as named arguments.

The output file contains the columns X and SYS_ERR.

Examples

Write out the systematic errors from the default data set to the file ‘errs.dat’.

>>> save_syserror('errs.dat')

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

>>> save_syserror('jet', 'err.out', clobber=True)

Write the data out in FITS format:

>>> save_syserror('syserr.fits', ascii=False)