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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine sormr3 | ( | character | SIDE, |
character | TRANS, | ||
integer | M, | ||
integer | N, | ||
integer | K, | ||
integer | L, | ||
real, dimension( lda, * ) | A, | ||
integer | LDA, | ||
real, dimension( * ) | TAU, | ||
real, dimension( ldc, * ) | C, | ||
integer | LDC, | ||
real, dimension( * ) | WORK, | ||
integer | INFO | ||
) |
SORMR3 multiplies a general matrix by the orthogonal matrix from a RZ factorization determined by stzrzf (unblocked algorithm).
Download SORMR3 + dependencies [TGZ] [ZIP] [TXT]
SORMR3 overwrites the general real m by n matrix C with Q * C if SIDE = 'L' and TRANS = 'N', or Q**T* C if SIDE = 'L' and TRANS = 'C', or C * Q if SIDE = 'R' and TRANS = 'N', or C * Q**T if SIDE = 'R' and TRANS = 'C', where Q is a real orthogonal matrix defined as the product of k elementary reflectors Q = H(1) H(2) . . . H(k) as returned by STZRZF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'.
[in] | SIDE | SIDE is CHARACTER*1 = 'L': apply Q or Q**T from the Left = 'R': apply Q or Q**T from the Right |
[in] | TRANS | TRANS is CHARACTER*1 = 'N': apply Q (No transpose) = 'T': apply Q**T (Transpose) |
[in] | M | M is INTEGER The number of rows of the matrix C. M >= 0. |
[in] | N | N is INTEGER The number of columns of the matrix C. N >= 0. |
[in] | K | K is INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. |
[in] | L | L is INTEGER The number of columns of the matrix A containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. |
[in] | A | A is REAL array, dimension (LDA,M) if SIDE = 'L', (LDA,N) if SIDE = 'R' The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by STZRZF in the last k rows of its array argument A. A is modified by the routine but restored on exit. |
[in] | LDA | LDA is INTEGER The leading dimension of the array A. LDA >= max(1,K). |
[in] | TAU | TAU is REAL array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by STZRZF. |
[in,out] | C | C is REAL array, dimension (LDC,N) On entry, the m-by-n matrix C. On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q. |
[in] | LDC | LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). |
[out] | WORK | WORK is REAL array, dimension (N) if SIDE = 'L', (M) if SIDE = 'R' |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value |
Definition at line 180 of file sormr3.f.