Module functions to get the error estimates of source and background datasets.
Array_Type get_errors([Integer_Type])
Array_Type get_berrors([Integer_Type])
Array_Type get_full_errors([Integer_Type])
Array_Type get_full_berrors([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 error estimates
associated with input datasets.
The ones without full in the name return
arrays comprised of error estimates within the applied filter;
those with full in the name
retrieve the unfiltered 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 error estimates
may be displayed, e.g., via the
Sherpa plotting commands
LPLOT ERRORS
and
LPLOT BERRORS.
sherpa> DATA spec.dat
sherpa> e = get_errors(1)
sherpa> printarr(e,2)
8.72981
7.8374
sherpa> e[0] = 5
sherpa> () = set_errors(1,e)
sherpa> write errors
Write X-Axis: Bin Y-Axis: Errors
1 5
2 7.8374
- chandra
-
guide
- sherpa
-
get_analysis,
get_arf_axes,
get_axes,
get_coord,
get_data,
get_energy_axes,
get_filter,
get_filter_expr,
get_fit,
get_fluxed_spectrum,
get_ftest,
get_metadata,
get_photon_axes,
get_photon_energy_axes,
get_photon_wave_axes,
get_qvalue,
get_raw_axes,
get_record,
get_source,
get_statistic,
get_stats,
get_syserrors,
get_wave_axes,
get_weights,
record,
save,
write
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