trace

Sum of diagonal elements.

Syntax

b = trace(A)

Description

Returns the sum of the diagonal elements of A. Equivalent to sum(diag(A)). Defined for square and non-square matrices alike (sum runs along min(size(A))).

Examples

trace(magic(3))          % 15
trace(eye(5))            % 5

See also

• det — Determinant of a square matrix.
• rank — Numerical rank of a matrix.