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Last modified: December 2013

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AHELP for CIAO 4.9 Sherpa v1


Context: data


Unpack ASCII data from a crate


unpack_ascii( filename|crate, [ncols=2,colkeys=None,dstype=Data1D,sep="
",comment="#"] )


The unpack_ascii command unpacks tabular data from a column-based text file into a Sherpa data object.

If a filename is provided as input, a crate is created but hidden and cannot be used for other analysis in the session.

  • filename - the name of the file (with path) or crate which contains the data
  • ncols - number of columns to read; default=2
  • colkeys - list of column names; default=None
  • sep - the column-separating character; default is a space (" ")
  • comment - character which indicates a comment line; default=#
  • dstype - dataset type: Data1D, Data1DInt, Data2D, Data2DInt; default=Data1D

Example 1

sherpa> src = unpack_ascii("data.txt", ncols=3)

Unpack the first three columns of data.txt into the data object "src".

Example 2

sherpa> tabdat = unpack_ascii("tabbed.txt", sep="\t")

Unpack ASCII data from tabbed.txt, which uses a tab as the separator character.

Example 3

sherpa> rprof = unpack_ascii("radpro.txt[cols RMID, SUR_BRI,
SUR_BRI_ERR]", dstype=Data1D)
sherpa> rprof = unpack_ascii("radpro.txt", colkeys=["RMID", "SUR_BRI",
"SUR_BRI_ERR"], dstype=Data1D)

The two commands are equivalent. The columns RMID, SUR_BRI, and SUR_BRI_ERR are unpacked from the Data1D dataset radpro.txt. The default comment character and column separator are used.


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_plot, get_counts, get_data, get_data_plot, get_dep, get_dims, get_error, get_quality, get_specresp, get_staterror, get_syserror, group, load_arf, load_arrays, load_ascii, load_bkg, load_bkg_arf, 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_data, set_quality, ungroup, unpack_arf, unpack_arrays, 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_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, get_ratio, get_resid, histogram1d, histogram2d, image_data, rebin

Last modified: December 2013
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