set_arf¶
- sherpa.astro.ui.set_arf(id, arf=None, resp_id=None, bkg_id=None)¶
Set the ARF for use by a PHA data set.
Set the effective area curve for a PHA data set, or its background.
- Parameters
id (int or str, optional) – The data set to use. If not given then the default identifier is used, as returned by get_default_id.
arf – An ARF, such as returned by get_arf or unpack_arf.
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 this to identify the ARF as being for use with the background.
See also
get_arf
Return the ARF associated with a PHA data set.
load_arf
Load an ARF from a file and add it to a PHA data set.
load_pha
Load a file as a PHA data set.
set_full_model
Define the convolved model expression for a data set.
set_rmf
Set the RMF for use by a PHA data set.
unpack_arf
Read in an ARF from 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 arf parameter. If given two un-named arguments, then they are interpreted as the id and arf parameters, respectively. The remaining parameters are expected to be given as named arguments.
If a PHA data set has an associated ARF - either from when the data was loaded or explicitly with the set_arf function - then the model fit to the data will include the effect of the ARF when the model is created with set_model or set_source. In this case the get_source function returns the user model, and get_model the model that is fit to the data (i.e. it includes any response information; that is the ARF and RMF, if set). To include the ARF explicitly, use set_full_model.
Examples
Copy the ARF from the default data set to data set 2:
>>> arf1 = get_arf() >>> set_arf(2, arf1)
Read in an ARF from the file ‘bkg.arf’ and set it as the ARF for the background model of data set “core”:
>>> arf = unpack_arf('bkg.arf') >>> set_arf('core', arf, bkg_id=1)