Last modified: December 2020

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/set_arf.html
Jump to: Description · Examples · PARAMETERS · Notes · Bugs · See Also


AHELP for CIAO 4.13 Sherpa v1

set_arf

Context: data

Synopsis

Set the ARF for use by a PHA data set.

Syntax

set_arf(id, arf=None, resp_id=None, bkg_id=None)

id - int or str, optional
resp_id - int or str, optional
bkg_id - int or str, optional

Description

Set the effective area curve for a PHA data set, or its background.


Examples

Example 1

Copy the ARF from the default data set to data set 2:

>>> arf1 = get_arf()
>>> set_arf(2, arf1)

Example 2

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)

PARAMETERS

The parameters for this function are:

Parameter Definition
id 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 The identifier for the ARF within this data set, if there are multiple responses.
bkg_id Set this to identify the ARF as being for use with the background.

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` .


Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

confidence
set_conf_opt, set_covar_opt, set_proj_opt
data
get_arf, get_bkg, get_bkg_arf, get_bkg_model, get_bkg_rmf, get_bkg_source, load_arf, load_bkg_arf, load_multi_arfs, set_areascal, set_backscal, set_bkg, set_coord, set_counts, set_data, set_dep, set_exposure, set_grouping, set_quality, set_rmf, set_staterror, set_syserror, unpack_arf
filtering
set_filter
info
list_response_ids
methods
set_iter_method, set_iter_method_opt, set_method, set_method_opt
modeling
get_par, get_response, get_xsabund, get_xscosmo, get_xsxsect, get_xsxset, set_bkg_model, set_bkg_source, set_full_model, set_model, set_par, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxsect, set_xsxset
plotting
plot_arf
statistics
set_prior, set_sampler, set_sampler_opt, set_stat
utilities
set_analysis, set_default_id
visualization
image_setregion