Copositive matrix

In mathematics, specifically linear algebra, a real matrix A is copositive if
 * $$x^TAx\geq 0$$

for every nonnegative vector $$x\geq 0$$. The collection of all copositive matrices is a proper cone; it includes as a subset the collection of real positive-definite matrices.

Copositive matrices find applications in economics, operations research, and statistics.