get_rate

Context: utilities

Synopsis

Return the measured count rate of a data set

Syntax

get_rate( [id, filter=False, bkg_id] )

The get_rate() function returns the measured count rate of a source or background data set, by data id or bkg_id. For a data set in energy units, the count rate is Counts/sec/keV, for wavelength units the count rate is Counts/sec/Angstrom, and for channel units the count rate is Counts/sec.

If a data filter has been applied to the data set in question, e.g. ignore() or notice(), the count rate for either the filtered or unfiltered data set may be returned by setting the 'filter' argument to 'True' or 'False'. If set to 'True', the count rate array returned by get_rate() will be filtered, i.e. the array will be shorter in length than the unfiltered array (not padded with zeros).

id - the id of the data set to use; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")
filter - apply an established data filter to the data set before returning results? ; default=False
bkg_id - the id of the background to use, e.g. if more than one background is associated with the data; default is the first background dataset loaded

Example 1

sherpa> get_rate()

When called with no arguments, the get_rate() function returns the count rate array of the unfiltered default data set.

sherpa> get_rate()

array([ 0.        ,  0.        ,  0.        ,  0.        ,  0.        ,
        0.        ,  0.        ,  0.        ,  0.        ,  0.        ,
        0.        ,  0.00727432,  0.01212387,  0.00242477,  0.        ,
        0.        ,  0.00484955,  0.00484954,  0.01333627,  0.01454863,
        0.00484954,  0.00727431,  0.00484955,  0.00363716,  0.00606193,
 . . . . . . . . .,
       0.0012124 ,  0.00242481,  0.        ,  0.00363697,  0.00242481,
        0.        ,  0.0012124 ,  0.00242481,  0.00242465,  0.0012124 ,
        0.        ,  0.00363721,  0.0012124 ,  0.36006014])

Example 2

sherpa> get_rate(3, filter=True)

If a data set ID is supplied to get_rate(), the unfiltered count rate array of the specified data set is returned, unless the 'filter' argument is set to 'True'.

sherpa> notice()

sherpa> get_rate(3).size
           1024

sherpa> ignore(10.0, 12.0)

sherpa> get_rate(3, filter=True).size
           886

Example 3

sherpa> get_rate(4, bkg_id=2)

To return the dependent variable array of a background associated with a data set, the background ID must be specified along with the data set ID. Here, the second background loaded for data set 4 is returned by get_rate().

Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.