LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
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real function sqpt01 | ( | integer | M, |
integer | N, | ||
integer | K, | ||
real, dimension( lda, * ) | A, | ||
real, dimension( lda, * ) | AF, | ||
integer | LDA, | ||
real, dimension( * ) | TAU, | ||
integer, dimension( * ) | JPVT, | ||
real, dimension( lwork ) | WORK, | ||
integer | LWORK | ||
) |
SQPT01
SQPT01 tests the QR-factorization with pivoting of a matrix A. The array AF contains the (possibly partial) QR-factorization of A, where the upper triangle of AF(1:k,1:k) is a partial triangular factor, the entries below the diagonal in the first k columns are the Householder vectors, and the rest of AF contains a partially updated matrix. This function returns ||A*P - Q*R||/(||norm(A)||*eps*M)
[in] | M | M is INTEGER The number of rows of the matrices A and AF. |
[in] | N | N is INTEGER The number of columns of the matrices A and AF. |
[in] | K | K is INTEGER The number of columns of AF that have been reduced to upper triangular form. |
[in] | A | A is REAL array, dimension (LDA, N) The original matrix A. |
[in] | AF | AF is REAL array, dimension (LDA,N) The (possibly partial) output of SGEQPF. The upper triangle of AF(1:k,1:k) is a partial triangular factor, the entries below the diagonal in the first k columns are the Householder vectors, and the rest of AF contains a partially updated matrix. |
[in] | LDA | LDA is INTEGER The leading dimension of the arrays A and AF. |
[in] | TAU | TAU is REAL array, dimension (K) Details of the Householder transformations as returned by SGEQPF. |
[in] | JPVT | JPVT is INTEGER array, dimension (N) Pivot information as returned by SGEQPF. |
[out] | WORK | WORK is REAL array, dimension (LWORK) |
[in] | LWORK | LWORK is INTEGER The length of the array WORK. LWORK >= M*N+N. |
Definition at line 122 of file sqpt01.f.