Defines an expression or file to be used to specify the
systematic errors for source data.
sherpa> SYSERRORS [<dataset range> | ALLSETS] = <errorExpr>
SYSERRORS is used for specifying statistical errors in source datasets,
while BSYSERRORS is used for specifying statistical errors in
background datasets ("ahelp bsyserrors").
<dataset range> = # (or more generally #:#,#:#, etc.) such that #
specifies a dataset number and #:# represents an inclusive range of
datasets; one may specify multiple inclusive ranges by separating them
with commas. The default dataset is dataset 1.
The error expression, <errorExpr>, may be composed of one or
more (algebraically-combined) of the following elements:
| DATA | An input dataset |
| numericals | Numerical values |
| operators | + - * / ( ) |
A few things to note:
-
Systematic error expressions cannot be defined without first reading in
a source dataset.
-
The input systematic error for a given bin is first multiplied by the
datum in that bin; the resulting product is added in quadrature with
the statistical error to yield the overall error for that bin.
-
The systematic errors can be
specified in an input file; see READ
SYSERRORS for more information.
-
If the systematic errors are not defined using the
SYSERRORS command or input using READ SYSERRORS,
they are assumed to be zero.
For additional information, see the related command ERRORS.
The systematic errors are accessible to the Sherpa/S-Lang module
user via the functions
get_syserrors and
set_syserrors.
Define an expression to be used for the systematic errors. In
each bin, they will be computed as 0.1 times the datum.
sherpa> DATA data.dat
sherpa> SYSERRORS = 0.1
- sherpa
-
berrors,
bsyserrors,
compute_errors,
compute_statistic,
covariance,
errors,
ftest,
get_paramest,
get_paramestint,
get_paramestlim,
get_paramestreg,
goodness,
interval-projection,
interval-uncertainty,
list_paramest,
mlr,
projection,
region-projection,
region-uncertainty,
restore_paramest,
run_paramest,
run_paramestint,
run_paramestlim,
run_paramestreg,
set_errors,
set_syserrors,
staterrors,
uncertainty
|
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