Last modified: December 2023

AHELP for CIAO 4.16 Sherpa


Context: data


Load a data set from a file.


load_data(id, filename=None, *args, **kwargs)

id - int or str, optional


This loads a data set from the file, trying in order `load_pha` , `load_image` , `load_table` , then `load_ascii` .


Example 1

>>> load_data('tbl.dat')

Example 2

>>> load_data('hist.dat', dstype=Data1DInt)

Example 3

>>> load_data('img', 'img.fits')
>>> load_data('bg', 'img_bg.fits')

Example 4

>>> cols = ['rmid', 'sur_bri', 'sur_bri_err']
>>> load_data(2, 'profile.fits', colkeys=cols)


The parameters for this function are:

Parameter Definition
id The identifier for the data set to use. For multi-dataset files, currently only PHA2, the id value indicates the first dataset: if it is an integer then the numbering starts at id, and if a string then a suffix of 1 to n is added. If not given then the default identifier is used, as returned by `get_default_id` .
filename A file name or a data structure representing the data to use, as used by the I/O backend in use by Sherpa: e.g. a phacratedataset , tablecrate , or imagecrate for crates, as used by CIAO, or a list of AstroPy HDU objects.
args The arguments supported by `load_pha` , `load_image` , `load_table` , and `load_ascii` .
kwargs The keyword arguments supported by `load_pha` , `load_image` , `load_table` , and `load_ascii` .


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 the `id` and `filename` parameters, respectively. The remaining parameters are expected to be given as named arguments.

Changes in CIAO

Changed in CIAO 4.14

The id argument is now used to define the first identifier when loading in a PHA2 file to match `load_pha` (previously the range always started at 1).


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

See Also

copy_data, dataspace1d, dataspace2d, datastack, delete_data, fake, get_axes, get_bkg_chisqr_plot, get_bkg_delchi_plot, get_bkg_fit_plot, get_bkg_model_plot, get_bkg_plot, get_bkg_ratio_plot, get_bkg_resid_plot, get_bkg_source_plot, get_counts, get_data, get_data_contour, get_data_contour_prefs, get_data_image, get_data_plot, get_data_plot_prefs, get_dep, get_dims, get_error, get_quality, get_specresp, get_staterror, get_syserror, group, group_adapt, group_adapt_snr, group_bins, group_counts, group_snr, group_width, load_arf, load_arrays, load_ascii, load_bkg, load_bkg_arf, load_bkg_rmf, 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_data, set_quality, ungroup, unpack_arf, unpack_arrays, unpack_ascii, unpack_bkg, unpack_data, unpack_image, unpack_pha, unpack_rmf, unpack_table
get_filter, load_filter, set_filter
get_default_id, list_bkg_ids, list_data_ids, list_response_ids
add_model, add_user_pars, clean, load_table_model, load_template_interpolator, load_template_model, load_user_model, save_model, save_source
plot_data, set_xlinear, set_xlog, set_ylinear, set_ylog
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
calc_data_sum, calc_data_sum2d, calc_ftest, calc_kcorr, calc_mlr, calc_model_sum2d, calc_source_sum2d, get_rate
contour, contour_data, contour_ratio, histogram1d, histogram2d, image_data, rebin