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Last modified: December 2010

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AHELP for CIAO 4.3 Sherpa v1


Context: filtering


Apply an exclude region filter to all 2-D data sets


ignore2d( [val] )


Specifies a region mask to be excluded from all available 2-D data sets in a Sherpa session, using CIAO region syntax or a region file.

  • val - a filter defined by CIAO region syntax or a FITS or ASCII region filename (including path); default=None

The filter must be defined in the same coordinate system as the "coord" field of the data structure, which is returned by the get_coord command ("ahelp get_coord"). For information on the CIAO region filtering syntax, refer to "ahelp dmregions".

Example 1

sherpa> ignore2d()

The function ignore2d can be called with no arguments, in which case the filter will ignore all data points on the grid for all available 2-D data set ID(s).

Example 2

sherpa> ignore2d("circle(25,25,5)")
sherpa> ignore2d("circle(4300,3710,15)")
sherpa> ignore2d("circle(259.18823,67.14189,0.01)")

Supplying a region string in CIAO region syntax, such as "circle(x_center, y_center, radius)" in physical coordinates, will apply the region filter to all available 2-D data set ID(s).

Example 3

sherpa> !cat filter.reg
sherpa> ignore2d("filter.reg")

The ASCII region file filter.reg is used to filter all 2-D data sets. In this case we exclude all pixels within the circle centered at 4070,3940 and with a radius of 6.


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

See Also

get_filter, ignore, ignore2d_id, ignore_bad, ignore_id, notice, notice2d, notice2d_id, notice_id, show_filter

Last modified: December 2010
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