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Last modified: December 2010

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AHELP for CIAO 4.3 Sherpa v1


Context: data


Return the dependent variable array (e.g., counts) of a data set


get_dep( [id, filter=False, bkg_id] )


The get_dep() function returns the dependent variable array of a source or background data set, by data id or bkg_id; it produces the same results as the function get_counts(). If a data filter has been applied to the data set in question, e.g. ignore() or notice(), the dependent variable array for either the filtered or unfiltered data set may be returned by setting the 'filter' argument to 'True' or 'False'. If set to 'True', the array returned by get_dep() will be filtered, i.e. the array will be shorter in length than the unfiltered array (not padded with zeros).

  • id - the id of the data set to use; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")
  • filter - apply an established data filter to the data set before returning results? ; default=False
  • bkg_id - the id of the background to use, e.g. if more than one background is associated with the data; default=None

Example 1

sherpa> get_dep()

When called with no arguments, the get_dep() function returns the dependent variable array of the unfiltered default data set.

sherpa> get_data().counts
[   0.    0.    0. ...,    3.    1.  297.]

sherpa> get_dep()
           array([   0.,    0.,    0., ...,    3.,    1.,  297.])

Example 2

sherpa> get_dep(3, filter=True)

If a data set ID is supplied to get_dep(), the unfiltered dependent variable array of the specified data set is returned, unless the 'filter' argument is set to 'True'.

sherpa> get_dep(3)
           array([  0.,   0.,   0., ...,   1.,   0.,  76.])

sherpa> get_dep().size

sherpa> ignore(10.0, 15.0)

sherpa> get_dep(3, filter=True)
           array([  0.,   0.,   0., ...,   1.,   0.,  76.])

sherpa> get_dep(1, filter=True).size

Example 3

sherpa> get_dep(4, bkg_id=2)

To return the dependent variable array of a background associated with a data set, the background ID must be specified along with the data set ID. Here, the second background loaded for data set 4 is returned by get_dep().


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

See Also

get_conf, get_covar, get_int_proj, get_int_unc, get_proj, get_reg_proj, get_reg_unc
copy_data, dataspace1d, dataspace2d, delete_data, fake, get_areascal, get_arf, get_arf_plot, get_axes, get_backscal, get_bkg, get_bkg_plot, get_bkg_scale, get_coord, get_counts, get_data, get_data_plot, get_dims, get_error, get_exposure, get_grouping, get_indep, get_quality, get_rmf, get_specresp, get_staterror, get_syserror, group_sherpa, load_ascii, load_data, load_grouping, load_quality, set_data, set_quality, ungroup, unpack_ascii, unpack_data
get_filter, load_filter, set_filter
calc_stat_info, get_fit, get_stat_info
get_default_id, list_data_ids, list_response_ids, list_stats
get_iter_method_name, get_iter_method_opt, get_method
clean, get_model, get_model_component, get_model_component_image, get_model_component_plot, get_model_plot, get_num_par, get_order_plot, get_par, get_pileup_model, get_response, get_source, get_source_component_image, get_source_component_plot, image_source
get_split_plot, plot_data, set_xlinear, set_xlog, set_ylinear, set_ylog
get_kernel, get_psf
save_error, save_filter, save_grouping, save_quality, save_staterror, save_syserror
get_chisqr_plot, get_delchi_plot, get_stat
calc_data_sum, calc_data_sum2d, calc_ftest, calc_kcorr, calc_mlr, calc_model_sum2d, calc_source_sum2d, get_analysis, get_rate
contour, contour_data, contour_ratio, get_ratio, get_resid, histogram1d, histogram2d, image_data, image_getregion, rebin

Last modified: December 2010
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