# Command: MapIndexed

NEST HelpDesk | Command Index | NEST Quick Reference

Name:

    MapIndexed - Apply a function  to each element of a list/string

Synopsis:

      [v1 ... vn] {f} MapIndexed -> [ f(v1,1) ... f(vn,n) ]

Examples:

      [1 2 3 4 5]  {add} MapIndexed -> [2 4 6 8 10]
      (abcd) {add} MapIndexed -> (bdfh)

Description:

      For each element of the input array, MapIndexed calls f with
      two arguments, the current index and the element. It replaces
      the element with the result of f.
      MapIndexed works similar to Map, however, in adition to the
      element its index within the array is also passed to the function.
      Note that the index starts with 1, according to Mathematica convention.
      This is unlike in forallindexed where in accordance with Postscript
      array indices start with 0.
      The result of MapIndexed is a list with the same number of values as the
      argument list.
      If f does not return a value, MapIndexed fails.
      If f returns more than one value, the result of MapIndexed is
      undefined.

      Alternatives: Function MapIndexed_a for lists and  MapIndexed_s
      for strings (both undocumented) -> behaviour and synopsis are
      the same.

Parameters:

      [v1 ... vn]	- list of n arbitrary objects or string.

      {f}		- function of two arguments and one return value.

Bugs:

Diagnostics:

    None

References:

    The Mathematica Book

Author:

      Marc-Oliver Gewaltig

SeeAlso:

- Map
- Table
- forall
- forallindexed

Source:

    /opt/conda/conda-bld/nest_1531570948828/work/lib/sli/mathematica.sli

NEST HelpDesk | Command Index | NEST Quick Reference

© 2004 The NEST Initiative