Function: [nonneg, As] = verinvnonneg (A)

Verified nonnegative invertibility of an interval matrix.

For a square interval (or real) matrix A, this function verifies inverse nonnegativity of A, or not-inverse-nonnegativity of A, or yields no verified result:

nonneg = 1

A verified inverse nonnegative,

nonneg = 0

A verified not to be inverse nonnegative; As is a matrix in A (always one of the two bounds) which is verified not to be inverse nonnegative,

nonneg = -1

no verified result.

Based on the result by Kuttler, Math. of Computation 1971; see also J. Rohn, A Handbook of Results on Interval Linear Problems, posted at http://www.cs.cas.cz/~rohn, Section 3.9.

This work was supported by the Czech Republic National Research Program “Information Society”, project 1ET400300415.

See also: inv.

Package: interval