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LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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subroutine sopmtr | ( | character | side, |
character | uplo, | ||
character | trans, | ||
integer | m, | ||
integer | n, | ||
real, dimension( * ) | ap, | ||
real, dimension( * ) | tau, | ||
real, dimension( ldc, * ) | c, | ||
integer | ldc, | ||
real, dimension( * ) | work, | ||
integer | info | ||
) |
SOPMTR
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SOPMTR overwrites the general real M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'T': Q**T * C C * Q**T where Q is a real orthogonal matrix of order nq, with nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of nq-1 elementary reflectors, as returned by SSPTRD using packed storage: if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1); if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1).
[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] | UPLO | UPLO is CHARACTER*1 = 'U': Upper triangular packed storage used in previous call to SSPTRD; = 'L': Lower triangular packed storage used in previous call to SSPTRD. |
[in] | TRANS | TRANS is CHARACTER*1 = 'N': No transpose, apply Q; = 'T': Transpose, apply Q**T. |
[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] | AP | AP is REAL array, dimension (M*(M+1)/2) if SIDE = 'L' (N*(N+1)/2) if SIDE = 'R' The vectors which define the elementary reflectors, as returned by SSPTRD. AP is modified by the routine but restored on exit. |
[in] | TAU | TAU is REAL array, dimension (M-1) if SIDE = 'L' or (N-1) if SIDE = 'R' TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SSPTRD. |
[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 148 of file sopmtr.f.