Last modified: December 2013

URL: http://cxc.harvard.edu/sherpa/ahelp/set_staterror.html
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AHELP for CIAO 4.11 Sherpa v1

set_staterror

Context: data

Synopsis

Set the statistical errors

Syntax

set_staterror([id], val, [fractional,] [bkg_id])

Description

The set_staterror command sets the statistical errors for a dataset. The error value may be an array or a single value to be repeated for every bin. Setting the fractional argument uses the scalar value as the fractional portion of the dependent array as the errors.

Sherpa reads in the grouping flags from file and turns on grouping by default, if possible. The errors will be grouped if grouping is on.


Examples

Example 1

sherpa> set_staterror([0.040, 0.039, 0.041, ...])

Set the staterrors to an array of error values.

Example 2

sherpa> set_staterror(2, 0.04)

Set the statistical errors for dataset id=2 to 0.04 for all bins.

Example 3

sherpa> set_staterror(0.05, fractional=True)

Use a fractional portion (0.05) of the dependent array as the errors for the default dataset.


Bugs

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

See Also

confidence
set_conf_opt, set_covar_opt, set_proj_opt
data
set_areascal, set_arf, set_backscal, set_bkg, set_coord, set_counts, set_data, set_exposure, set_grouping, set_quality, set_rmf, set_syserror
filtering
set_filter
methods
set_iter_method, set_iter_method_opt, set_method, set_method_opt
modeling
get_par, set_bkg_model, set_full_model, set_par, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxsect, set_xsxset
statistics
set_prior, set_sampler, set_sampler_opt, set_stat
utilities
set_analysis, set_default_id
visualization
image_setregion