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Last modified: December 2013

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AHELP for CIAO 4.9 Sherpa v1


Context: data


Load a background ARF


load_bkg_arf( [id], filename|ARFCrate )


The load_bkg_arf command loads an ARF (effective area) from a FITS file or an ARFCrate. The ARF is assigned as the default response id for the default background id of the specified source dataset; i.e. for most simple analyses, this command will assign the ARF as the first response of the first background dataset associated with the id.

  • id - the id of the dataset to use; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")
  • filename|ARFCrate - the name of the file (with path) or ARFCrate which contains the ARF data

The load_bkg command ("ahelp load_bkg") may instead be used to load the background ARF. It allows the user to specify the background and response ids, in addition to the source dataset id.

Example 1

sherpa> load_bkg_arf("back.arf")
sherpa> load_bkg_arf(1, "back.arf")

Load the ARF from the file "back.arf" and assign it as the background ARF for the default dataset.

Example 2

sherpa> arfcr = read_arf("3c273.arf")
sherpa> load_bkg_arf("src", arfcr)

The ARF is read into an ARFCrate (named "arfcr") from the file 3c273.arf. The ARF is then loaded into Sherpa from the crate and assigned to the background of data id "src".


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

See Also

dataspace1d, dataspace2d, datastack, fake, get_arf, get_bkg, load_arf, load_arrays, load_ascii, load_bkg, load_bkg_rmf, load_data, load_grouping, load_image, load_multi_arfs, load_multi_rmfs, load_pha, load_quality, load_rmf, load_staterror, load_syserror, load_table, pack_image, pack_pha, pack_table, set_arf, unpack_arf, unpack_arrays, unpack_ascii, unpack_bkg, unpack_data, unpack_image, unpack_pha, unpack_rmf, unpack_table
get_default_id, list_bkg_ids, list_data_ids, list_response_ids
add_model, add_user_pars, get_response, load_table_model, load_template_model, load_user_model, save_model, save_source
save_arrays, save_data, save_delchi, save_error, save_filter, save_grouping, save_image, save_pha, save_quality, save_resid, save_staterror, save_syserror, save_table

Last modified: December 2013
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