Name

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    HIST_ND_WEIGHT

Purpose

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    Wrapper to the dfanning HIST_ND function that calculates a
    weighted multi-dimensional histogram.

Category

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    Math

Calling Sequence

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    Result = HIST_ND_WEIGHT(V, Bin)

Inputs

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    V: Values whose histogram is to be taken. V should be an NxP
        array for P points in N dimensions.
    Bin: Bin size. May either be a scalar, or an N-dimensional vector.

Keyword Parameters

---

    WEIGHT: A vector of the same dimensions as V with the weights
                  for each data value.
    UNWEIGHTED: Outputs the unweighted histogram.
    REVERSE_INDICES: Outputs the reverse index array.
    _EXTRA: All extra keywords are passed through to HIST_ND.

Outputs

---

    The function returns a multi-dimensional histogram where each data value
    has been weighted by its WEIGHT value. The return type is the same type
    as WEIGHT.

Example

---

    IDL> q = TRANSPOSE( [ [0.1*FINDGEN(40)], [0.2*FINDGEN(40)] ] )
    IDL> PRINT, HIST_ND_WEIGHT(q, 1, WEIGHT=q, UNWEIGHTED=plainhist)
        0.500000 0.00000 0.00000 0.00000
          2.50000 0.00000 0.00000 0.00000
          0.00000 4.00000 0.00000 0.00000
          0.00000 6.50000 0.00000 0.00000
          0.00000 0.00000 7.50000 0.00000
          0.00000 0.00000 10.5000 0.00000
          0.00000 0.00000 0.00000 11.0000
          0.00000 0.00000 0.00000 14.5000
    IDL> PRINT, plainhist
              5 0 0 0
              5 0 0 0
              0 5 0 0
              0 5 0 0
              0 0 5 0
              0 0 5 0
              0 0 0 5
              0 0 0 5
 

Modification History

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    Written by: Jeremy Bailin
    12 June 2008 Public release in JBIU
    17 June 2011 Bug fix for bins with no entries.