dqrt11.f - Man Page
TESTING/LIN/dqrt11.f
Synopsis
Functions/Subroutines
double precision function dqrt11 (m, k, a, lda, tau, work, lwork)
DQRT11
Function/Subroutine Documentation
double precision function dqrt11 (integer m, integer k, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork)
DQRT11
Purpose:
DQRT11 computes the test ratio || Q'*Q - I || / (eps * m) where the orthogonal matrix Q is represented as a product of elementary transformations. Each transformation has the form H(k) = I - tau(k) v(k) v(k)' where tau(k) is stored in TAU(k) and v(k) is an m-vector of the form [ 0 ... 0 1 x(k) ]', where x(k) is a vector of length m-k stored in A(k+1:m,k).
- Parameters
M
M is INTEGER The number of rows of the matrix A.
K
K is INTEGER The number of columns of A whose subdiagonal entries contain information about orthogonal transformations.
A
A is DOUBLE PRECISION array, dimension (LDA,K) The (possibly partial) output of a QR reduction routine.
LDA
LDA is INTEGER The leading dimension of the array A.
TAU
TAU is DOUBLE PRECISION array, dimension (K) The scaling factors tau for the elementary transformations as computed by the QR factorization routine.
WORK
WORK is DOUBLE PRECISION array, dimension (LWORK)
LWORK
LWORK is INTEGER The length of the array WORK. LWORK >= M*M + M.
- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 97 of file dqrt11.f.
Author
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Referenced By
The man page dqrt11(3) is an alias of dqrt11.f(3).
Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK