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:
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
get_default_id
.filename (str) – The name of the file to write the array to. The format is determined by the
ascii
argument.bkg_id (int, str, or None, optional) – Set if the background should be written out rather than the source.
ascii (bool, optional) – If
False
then the data is written as a FITS format binary table. The default isTrue
. The exact format of the output file depends on the I/O library in use (Crates or AstroPy).clobber (bool, optional) – If
outfile
is notNone
, 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 andclobber
isFalse
.
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 theid
andfilename
parameters, respectively. The remaining parameters are expected to be given as named arguments.The output file contains the columns
X
andSYS_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)