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Last modified: December 2010

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AHELP for CIAO 4.3 Sherpa v1


Context: filtering


Apply an exclude filter to all 1D data sets


ignore( [lo,hi] )
ignore( expr )


Specifies an interval of 1D data to be excluded in all available data sets in a Sherpa session. To operate on specific data sets by ID, use the ignore_id command ("ahelp ignore_id").

  • lo: lower bound of the filter; default=None
  • hi: upper bound of the filter; default=None
  • expr: a filter expression to ignore an intersection of filters, e.g. "0.1:5, 6:7". Range filtering allows ":#" and "#:", which excludes an open-ended range of data up to or beginning at the given value (#), respectively.

The units for the limits are determined by the "units" field of the data structure: channels, energy (keV), or wavelength (angstrom). The value can be obtained by using the get_analysis command ("ahelp get_analysis").

If the data is binned and the endpoint of the interval falls within a bin, the entire bin is included in the filter.

Two-dimensional Data Filtering

To apply an exclude filter to 2D data, use the ignore2d command ("ahelp ignore2d") or the ignore2d_id command ("ahelp ignore2d_id").

Example 1

sherpa> ignore()

The function ignore can be called with no arguments, in which case the filter will ignore all data points on the grid for all available data set IDs.

Example 2

sherpa> ignore(0.1, 6.0)

Supplying an interval will apply a filter to all available data set IDs.

Example 3

sherpa> ignore("0.1:5, 6:7")

Ignore the bins between 0.1 and 5 keV and between 6 and 7 keV.

Example 4

sherpa> ignore(7.,None)
sherpa> ignore(None, 0.5)

An interval with the default lower bound will filter all data points on the grid below the specified upper bound. An interval with the default upper bound will filter all data points on the grid above the specified lower bound.


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

See Also

get_filter, ignore2d, ignore2d_id, ignore_bad, ignore_id, notice, notice2d, notice2d_id, notice_id, show_filter

Last modified: December 2010
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