zgqrts.f - Man Page

subroutine zgqrts (n, m, p, a, af, q, r, lda, taua, b, bf, z, t, bwk, ldb, taub, work, lwork, rwork, result)
ZGQRTS

ZGQRTS

Purpose:

 ZGQRTS tests ZGGQRF, which computes the GQR factorization of an
 N-by-M matrix A and a N-by-P matrix B: A = Q*R and B = Q*T*Z.

Parameters

N

          N is INTEGER
          The number of rows of the matrices A and B.  N >= 0.

M

          M is INTEGER
          The number of columns of the matrix A.  M >= 0.

P

          P is INTEGER
          The number of columns of the matrix B.  P >= 0.

A

          A is COMPLEX*16 array, dimension (LDA,M)
          The N-by-M matrix A.

AF

          AF is COMPLEX*16 array, dimension (LDA,N)
          Details of the GQR factorization of A and B, as returned
          by ZGGQRF, see CGGQRF for further details.

Q

          Q is COMPLEX*16 array, dimension (LDA,N)
          The M-by-M unitary matrix Q.

R

          R is COMPLEX*16 array, dimension (LDA,MAX(M,N))

LDA

          LDA is INTEGER
          The leading dimension of the arrays A, AF, R and Q.
          LDA >= max(M,N).

TAUA

          TAUA is COMPLEX*16 array, dimension (min(M,N))
          The scalar factors of the elementary reflectors, as returned
          by ZGGQRF.

B

          B is COMPLEX*16 array, dimension (LDB,P)
          On entry, the N-by-P matrix A.

BF

          BF is COMPLEX*16 array, dimension (LDB,N)
          Details of the GQR factorization of A and B, as returned
          by ZGGQRF, see CGGQRF for further details.

Z

          Z is COMPLEX*16 array, dimension (LDB,P)
          The P-by-P unitary matrix Z.

T

          T is COMPLEX*16 array, dimension (LDB,max(P,N))

BWK

          BWK is COMPLEX*16 array, dimension (LDB,N)

LDB

          LDB is INTEGER
          The leading dimension of the arrays B, BF, Z and T.
          LDB >= max(P,N).

TAUB

          TAUB is COMPLEX*16 array, dimension (min(P,N))
          The scalar factors of the elementary reflectors, as returned
          by DGGRQF.

WORK

          WORK is COMPLEX*16 array, dimension (LWORK)

LWORK

          LWORK is INTEGER
          The dimension of the array WORK, LWORK >= max(N,M,P)**2.

RWORK

          RWORK is DOUBLE PRECISION array, dimension (max(N,M,P))

RESULT

          RESULT is DOUBLE PRECISION array, dimension (4)
          The test ratios:
            RESULT(1) = norm( R - Q'*A ) / ( MAX(M,N)*norm(A)*ULP)
            RESULT(2) = norm( T*Z - Q'*B ) / (MAX(P,N)*norm(B)*ULP)
            RESULT(3) = norm( I - Q'*Q ) / ( M*ULP )
            RESULT(4) = norm( I - Z'*Z ) / ( P*ULP )

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 174 of file zgqrts.f.