Module functions to get the systematic error estimates of source and background datasets.
Array_Type get_syserrors([Integer_Type])
Array_Type get_bsyserrors([Integer_Type])
Array_Type get_full_syserrors([Integer_Type])
Array_Type get_full_bsyserrors([Integer_Type])
Error Return Value: NULL
Arguments:
(1) data set number (default 1)
In a typical analysis involving module functions, a user will not seek
to manipulate the axes (which are useful primarily for plotting),
but to manipulate amplitudes
(i.e., y in the expression
y = f(x_0, x_1,...,x_(N-1)).)
A very simple example would be smoothing of data; a more complex example
would be the setting of error estimates iteratively in a manner not
supported by Sherpa.
First the user would ``get'' the error array, then process it,
then ``set'' it back into Sherpa.
These functions return arrays containing the current systematic
error estimates associated with input datasets.
(The quantities are the systematic errors multiplied by the data
in each bin, thus one may want to also retrieve the data and divide
by them to yield quantities that may be input into set_syserrors.)
The ones without full in the name return
arrays comprised of systematic error estimates within the applied filter;
those with full in the name
retrieve the unfiltered systematic error estimates.
(If the goal is to use these functions to manipulate data, and to set
these data back into Sherpa, it is important not
to change the filter in Sherpa between calling the get and
set functions!)
Source and background systematic errors
may be displayed, e.g., via the
Sherpa plotting commands
LPLOT SYSERRORS
and
LPLOT BSYSERRORS.
Retrieve and display systematic errors:
sherpa> data example.pha
The inferred file type is PHA. If this is not what you want, please
specify the type explicitly in the data command.
WARNING: using systematic errors specified in the PHA file.
RMF is being input from:
/data/simteste/Testing/sherpaTest/data/example2.rmf
ARF is being input from:
/data/simteste/Testing/sherpaTest/data/example2.arf
Background data are being input from:
/data/simteste/Testing/sherpaTest/data/example2_bkg.pha
sherpa> syserr = get_full_syserrors()
sherpa> printarr(syserr,3)
0
0
0
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