This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.

MapIndexed

 MapIndexedapplies f to the elements of expr, giving the part specification of each element as a second argument to f. MapIndexedapplies f to all parts of expr on levels specified by levelspec.
 n levels through n Infinity levels through Infinity {n} level n only {n1,n2} levels through
• The default value for levelspec in MapIndexed is .
• A positive level n consists of all parts of expr specified by n indices.
• A negative level -n consists of all parts of expr with depth n.
• Level consists of numbers, symbols, and other objects that do not have subparts.
• Level corresponds to the whole expression.
• With the option setting Heads->True, MapIndexed also applies to heads of expressions and their parts.
• MapIndexed traverses the parts of expr in a depth-first order, with leaves visited before roots. »
• MapIndexed always effectively constructs a complete new expression and then evaluates it.
gives the indices of each part:
 Out[1]=

gives the indices of each part:
 Out[1]=

 Out[1]=
 Out[2]=
 Scope   (6)
Map at level (default):
Map down to level :
Map at level :
Map down to level :
Map onto all elements of an expression:
Map only onto the "leaves" of the expression:
Negative levels:
Map on levels through ; the head has index :
MapIndexed can be used on expressions with any head:
The function can be mapped onto the heads as well:
MapIndexed works on sparse arrays:
 Options   (2)
By default, the function is not mapped onto the heads:
Map onto the heads at all levels:
 Applications   (5)
Label parts by position:
Use tooltips to show part numbers of subexpressions:
Convert a list to a polynomial:
Rotate lists based on position:
Obtain a list of all parts in an expression:
Leaves are visited before roots:
Using only the first argument is equivalent to using Map:
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