## cost

Cos by tau approximation.

Cos by tau approximation.

[F, e, n] = cost(A)

F = cost(A) approximates cos(A) by tau method .

x = itau object.

A = any matrix.

F = polynomial approximation of cos(M) in [a, b] evaluated (with orthovalM) in argument M = matrixM(x) = M(x). (double matrix).

schursolver and orthovalM.