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REBIN

Performs rebinning of any binned dataset up to 7-D. It has several operating modes which are selected by the OPT parameter. In the simplest and default mode a binning ratio is given for each axis and REBIN groups bins together in this ratio regardless of whether the input axes are regularly binned or are irregular. Other modes bin any input data into regular output bins determined either by the bin width or the total number of output bins for each axis. More complex modes allow the user to specify the boundaries for every bin using the standard format for ranges or by cloning the new axis values from another dataset. The latter method may be particularly useful for datasets with large numbers of points where it would be impractical to type in the bin bounds at the prompt. Instead the axis values and widths could be put into a text file and then TXT2ASTed to a dummy dataset that REBIN could then clone the output axes from. Data normalisation with respect to each axis remains unchanged between input and output. For datasets of dimension > 1 the user has the option of selecting which axes are to be rebinned. When using the clone option there is a restriction on this in that either all or just one axis may be selected.

The behaviour of the modes specified by OPT is,

  1. Specify a rebinning ratio for each axis (>=1) eg. if the ratio is 4, then 4 input bins are collected into each output bin
  2. Specify the number of bins for each output axis, the input data will be distributed into this number of regular output bins, which may be greater or smaller than the number input
  3. Specify a single, uniform bin width for each output axis
  4. Specify the bounds for each bin of each axis
  5. Clone the output axes from another dataset
See also the help on SASSBIN for binning specific to ROSAT XRT data.


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