dopmtr.f (3) - Linux Manuals
NAME
dopmtr.f -
SYNOPSIS
Functions/Subroutines
subroutine dopmtr (SIDE, UPLO, TRANS, M, N, AP, TAU, C, LDC, WORK, INFO)
DOPMTR
Function/Subroutine Documentation
subroutine dopmtr (characterSIDE, characterUPLO, characterTRANS, integerM, integerN, double precision, dimension( * )AP, double precision, dimension( * )TAU, double precision, dimension( ldc, * )C, integerLDC, double precision, dimension( * )WORK, integerINFO)
DOPMTR
Purpose:
-
DOPMTR 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 DSPTRD 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).
Parameters:
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SIDE
SIDE is CHARACTER*1 = 'L': apply Q or Q**T from the Left; = 'R': apply Q or Q**T from the Right.
UPLOUPLO is CHARACTER*1 = 'U': Upper triangular packed storage used in previous call to DSPTRD; = 'L': Lower triangular packed storage used in previous call to DSPTRD.
TRANSTRANS is CHARACTER*1 = 'N': No transpose, apply Q; = 'T': Transpose, apply Q**T.
MM is INTEGER The number of rows of the matrix C. M >= 0.
NN is INTEGER The number of columns of the matrix C. N >= 0.
APAP is DOUBLE PRECISION 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 DSPTRD. AP is modified by the routine but restored on exit.
TAUTAU is DOUBLE PRECISION 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 DSPTRD.
CC is DOUBLE PRECISION 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.
LDCLDC is INTEGER The leading dimension of the array C. LDC >= max(1,M).
WORKWORK is DOUBLE PRECISION array, dimension (N) if SIDE = 'L' (M) if SIDE = 'R'
INFOINFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value
Author:
-
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
- November 2011
Definition at line 150 of file dopmtr.f.
Author
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