LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
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subroutine sorg2r | ( | integer | M, |
integer | N, | ||
integer | K, | ||
real, dimension( lda, * ) | A, | ||
integer | LDA, | ||
real, dimension( * ) | TAU, | ||
real, dimension( * ) | WORK, | ||
integer | INFO | ||
) |
SORG2R generates all or part of the orthogonal matrix Q from a QR factorization determined by sgeqrf (unblocked algorithm).
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SORG2R generates an m by n real matrix Q with orthonormal columns, which is defined as the first n columns of a product of k elementary reflectors of order m Q = H(1) H(2) . . . H(k) as returned by SGEQRF.
[in] | M | M is INTEGER The number of rows of the matrix Q. M >= 0. |
[in] | N | N is INTEGER The number of columns of the matrix Q. M >= N >= 0. |
[in] | K | K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0. |
[in,out] | A | A is REAL array, dimension (LDA,N) On entry, the i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by SGEQRF in the first k columns of its array argument A. On exit, the m-by-n matrix Q. |
[in] | LDA | LDA is INTEGER The first dimension of the array A. LDA >= max(1,M). |
[in] | TAU | TAU is REAL array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SGEQRF. |
[out] | WORK | WORK is REAL array, dimension (N) |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value |
Definition at line 116 of file sorg2r.f.