load_staterror
- sherpa.ui.load_staterror(id, filename=None, ncols=2, *args, **kwargs)
Load the statistical errors from an ASCII file.
Read in a column or image from a file and use the values as the statistical errors for a data set. This over rides the errors calculated by any statistic, such as
chi2gehrels
orchi2datavar
.- Parameters:
id (int or str, optional) – The identifier for the data set to use. If not given then the default identifier is used, as returned by
get_default_id
.filename (str) – The name of the ASCII file to read in.
ncols (int, optional) – The number of columns to read in (the first
ncols
columns in the file).colkeys (array of str, optional) – An array of the column name to read in. The default is
None
.sep (str, optional) – The separator character. The default is
' '
.comment (str, optional) – The comment character. The default is
'#'
.
See also
get_staterror
Return the statistical error on the dependent axis of a data set.
load_syserror
Load the systematic errors from a file.
set_staterror
Set the statistical errors on the dependent axis of a data set.
set_stat
Set the statistical method.
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 theid
andfilename
parameters, respectively. The remaining parameters are expected to be given as named arguments.See
unpack_data
for a description of the supported file format.Examples
Read in the first column from ‘tbl.dat’:
>>> load_staterror('tbl.dat')
Use the column labelled ‘col3’
>>> load_staterror('tbl.dat', colkeys=['col3'])
Read in the first column from the file ‘errors.dat’ as the statistical errors for the ‘core’ data set:
>>> load_staterror('core', 'errors.dat')