An investigation is made of the Eigenstructure of a class of lower triangular moment matrices which arose in the context of finding the forced response of IIR filters to typical excitations. It is found that the Jordan matrix can have at most two types of Jordan blocks. The modal matrix is shown to have a peculiar structure where the progenitors in the column partitions corresponding to the Jor...

We consider a generic Iwahori–Hecke algebra H associated with a finite Weyl group. Any specialization of H gives rise to a corresponding decomposition matrix, and we show that the problem of computing that matrix can be interpreted in terms of Lusztig’s map from H to the asymptotic algebra J . This interpretation allows us to prove that the decomposition matrices always have a lower uni-triangu...

The Schur method for computing a matrix square root reduces the matrix to the Schur triangular form and then computes a square root of the triangular matrix. We show that by using a recursive blocking technique the computation of the square root of the triangular matrix can be made rich in matrix multiplication. Numerical experiments making appropriate use of level 3 BLAS show significant speed...

In this paper the degree of approximation function f, which is periodic with respect to hexagon lattice by matrix means T(A)n(f) its hexagonal Fourier series in generalized H?lder metric, where A a lower triangular infinite nonnegative real numbers nonincreasing row estimated.

Given a complex matrix H, we consider the decomposition H = QRP∗, where R is upper triangular and Q and P have orthonormal columns. Special instances of this decomposition include the singular value decomposition (SVD) and the Schur decomposition where R is an upper triangular matrix with the eigenvalues of H on the diagonal. We show that any diagonal for R can be achieved that satisfies Weyl’s...