Last modified: December 2021

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/load_data.html
AHELP for CIAO 4.14 Sherpa

load_data

Context: data

Synopsis

Load a data set from a file.

Syntax

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

id - int or str, optional

Description

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


Examples

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)

PARAMETERS

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` .

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 `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).


Bugs

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

See Also

data
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
filtering
get_filter, load_filter, set_filter
info
get_default_id, list_bkg_ids, list_data_ids, list_response_ids
modeling
add_model, add_user_pars, clean, load_table_model, load_template_interpolator, load_template_model, load_user_model, save_model, save_source
plotting
plot_data, set_xlinear, set_xlog, set_ylinear, set_ylog
saving
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
statistics
load_user_stat
utilities
calc_data_sum, calc_data_sum2d, calc_ftest, calc_kcorr, calc_mlr, calc_model_sum2d, calc_source_sum2d, get_rate
visualization
contour, contour_data, contour_ratio, histogram1d, histogram2d, image_data, rebin