MATLAB Function Reference Previous page   Next Page

Convert numeric values to logical



K = logical(A) returns an array that can be used for logical indexing or logical tests.

A(B), where B is a logical array, returns the values of A at the indices where the real part of B is nonzero. B must be the same size as A.


Most arithmetic operations remove the logicalness from an array. For example, adding zero to a logical array removes its logical characteristic. A = +A is the easiest way to convert a logical array, A, to a numeric double array.

Logical arrays are also created by the relational operators (==,<,>,~, etc.) and functions like any, all, isnan, isinf, and isfinite.


Given A = [1 2 3; 4 5 6; 7 8 9], the statement B = logical(eye(3)) returns a logical array

which can be used in logical indexing that returns A's diagonal elements:

However, attempting to index into A using the numeric array eye(3) results in:

See Also

islogical, logical operators (elementwise and short-circuit),

Previous page  log2 Logical Operators: Elementwise & | ~ Next page

© 1994-2005 The MathWorks, Inc.