TESTING/EIG/dgrqts.f(3) Library Functions Manual TESTING/EIG/dgrqts.f(3) NAME TESTING/EIG/dgrqts.f SYNOPSIS Functions/Subroutines subroutine dgrqts (m, p, n, a, af, q, r, lda, taua, b, bf, z, t, bwk, ldb, taub, work, lwork, rwork, result) DGRQTS Function/Subroutine Documentation subroutine dgrqts (integer m, integer p, integer n, double precision, dimension( lda, * ) a, double precision, dimension( lda, * ) af, double precision, dimension( lda, * ) q, double precision, dimension( lda, * ) r, integer lda, double precision, dimension( * ) taua, double precision, dimension( ldb, * ) b, double precision, dimension( ldb, * ) bf, double precision, dimension( ldb, * ) z, double precision, dimension( ldb, * ) t, double precision, dimension( ldb, * ) bwk, integer ldb, double precision, dimension( * ) taub, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork, double precision, dimension( 4 ) result) DGRQTS Purpose: !> !> DGRQTS tests DGGRQF, which computes the GRQ factorization of an !> M-by-N matrix A and a P-by-N matrix B: A = R*Q and B = Z*T*Q. !> Parameters M !> M is INTEGER !> The number of rows of the matrix A. M >= 0. !> P !> P is INTEGER !> The number of rows of the matrix B. P >= 0. !> N !> N is INTEGER !> The number of columns of the matrices A and B. N >= 0. !> A !> A is DOUBLE PRECISION array, dimension (LDA,N) !> The M-by-N matrix A. !> AF !> AF is DOUBLE PRECISION array, dimension (LDA,N) !> Details of the GRQ factorization of A and B, as returned !> by DGGRQF, see SGGRQF for further details. !> Q !> Q is DOUBLE PRECISION array, dimension (LDA,N) !> The N-by-N orthogonal matrix Q. !> R !> R is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (min(M,N)) !> The scalar factors of the elementary reflectors, as returned !> by DGGQRC. !> B !> B is DOUBLE PRECISION array, dimension (LDB,N) !> On entry, the P-by-N matrix A. !> BF !> BF is DOUBLE PRECISION array, dimension (LDB,N) !> Details of the GQR factorization of A and B, as returned !> by DGGRQF, see SGGRQF for further details. !> Z !> Z is DOUBLE PRECISION array, dimension (LDB,P) !> The P-by-P orthogonal matrix Z. !> T !> T is DOUBLE PRECISION array, dimension (LDB,max(P,N)) !> BWK !> BWK is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (min(P,N)) !> The scalar factors of the elementary reflectors, as returned !> by DGGRQF. !> WORK !> WORK is DOUBLE PRECISION array, dimension (LWORK) !> LWORK !> LWORK is INTEGER !> The dimension of the array WORK, LWORK >= max(M,P,N)**2. !> RWORK !> RWORK is DOUBLE PRECISION array, dimension (M) !> RESULT !> RESULT is DOUBLE PRECISION array, dimension (4) !> The test ratios: !> RESULT(1) = norm( R - A*Q' ) / ( MAX(M,N)*norm(A)*ULP) !> RESULT(2) = norm( T*Q - Z'*B ) / (MAX(P,N)*norm(B)*ULP) !> RESULT(3) = norm( I - Q'*Q ) / ( N*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 dgrqts.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/EIG/dgrqts.f(3)