Command: arraylib::IndexWrap

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Name:
 arraylib::IndexWrap - project a cyclic index value onto interval [0,N).

Synopsis:
  index N CyclicValue -> normindex

Description:
 
  "IndexWrap" projects a cyclic integer index in the range (-oo,oo),
  of periodicy N, onto its norm interval [0,N).
    
  This function can be used to "wrap around" array indices in order to
  index an array

  Alternatives: Function IndexWrap_i_i (undocumented) -> behaviour and
  synopsis are the same, except that no warnings or error messages are
  thrown.

Parameters:
 
  In : index: integer value in (-oo,oo).

       N: Peroidicity of the cyclic index.
          "index" is projected on the half-open interval [0,N).
          N must be positive (and different from 0).

  Out: The cyclic equivalent of the given index, regarding period N.

Diagnostics:
  N must be positive (and different from 0). If N <= 0, /RangeCheck is raised.
  Note that the variant IndexWrap_i_i does not do this check for
  efficiency, and will break or yield invalid results in this case.

Examples:
  -6 3 IndexWrap   -> 0        
  -5 3 IndexWrap   -> 1         
  -4 3 IndexWrap   -> 2        
  -3 3 IndexWrap   -> 0         
  -2 3 IndexWrap   -> 1         
  -1 3 IndexWrap   -> 2         
   0 3 IndexWrap   -> 0         
   1 3 IndexWrap   -> 1        
   2 3 IndexWrap   -> 2         
   3 3 IndexWrap   -> 0         
   4 3 IndexWrap   -> 1         
   5 3 IndexWrap   -> 2         
   6 3 IndexWrap   -> 0         

Availability:
"Namespace"-dictionary "arraylib".

Author:
 Ruediger Kupper

FirstVersion:
 14.2.2003 (Einstein's birthday)

Remarks:
 
  This function behaves like Mathematica's Mod function (which is
  different from the mathematical definition of MOD).

SeeAlso:arraylib::EdgeWrap mod CyclicValue
Source:
 /home/abuild/rpmbuild/BUILD/nest-2.4.1/lib/sli/arraylib.sli

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