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.

id - the id of the dataset to use; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")
val - array or scalar error values
fractional - use a fractional portion of the dependent array as the error? default=False . May be set to True , only if the "val" is a scalar.
bkg_id - the id of the background, if setting the background value; default=None

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.