load_ascii

Synopsis

Load an ASCII file as a data set.

load_ascii(id, filename=None, ncols=2, colkeys=None, dstype=Data1D,
sep=' ', comment='#')

id - int or str, optional
filename - str
ncols - int, optional
colkeys - array of str, optional
sep - str, optional
comment - str, optional
dstype - optional

Description

The standard behavior is to create a single data set, but multiple data sets can be loaded with this command, as described in the `sherpa.astro.datastack` module.

Examples

Example 1

Read in the first two columns of the file, as the independent (X) and dependent (Y) columns of the default data set:

>>> load_ascii('sources.dat')

Example 2

Read in the first three columns (the third column is taken to be the error on the dependent variable):

>>> load_ascii('sources.dat', ncols=3)

Example 3

Read in from columns 'RMID' and 'SUR_BRI' into data set 'prof':

>>> load_ascii('prof', 'rprof.dat',
...            colkeys=['RMID', 'SUR_BRI'])

Example 4

The first three columns are taken to be the two independent axes of a two-dimensional data set ( x0 and x1 ) and the dependent value ( y ):

>>> load_ascii('fields.txt', ncols=3,
...            dstype=Data2D)

Example 5

When using the Crates I/O library, the file name can include CIAO Data Model syntax, such as column selection. This can also be done using the colkeys parameter, as shown above:

>>> load_ascii('prof',
...            'rprof.dat[cols rmid,sur_bri,sur_bri_err]',
...            ncols=3)

PARAMETERS

The parameters for this function are:

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.

The column order for the different data types are as follows, where x indicates an independent axis and y the dependent axis.

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_with_errors, 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_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