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cupmtr-f(3)

cupmtr.f –

Synopsis

Functions/Subroutines

subroutine cupmtr (SIDE, UPLO, TRANS, M, N, AP, TAU, C, LDC, WORK, INFO)
CUPMTR

Function/Subroutine Documentation

subroutine cupmtr (characterSIDE, characterUPLO, characterTRANS, integerM, integerN, complex, dimension( * )AP, complex, dimension( * )TAU, complex, dimension( ldc, * )C, integerLDC, complex, dimension( * )WORK, integerINFO)

CUPMTR

Purpose:

 CUPMTR overwrites the general complex M-by-N matrix C with
 SIDE = 'L' SIDE = 'R'
 TRANS = 'N': Q * C C * Q
 TRANS = 'C': Q**H * C C * Q**H
 where Q is a complex unitary 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 CHPTRD 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:

SIDE

 SIDE is CHARACTER*1
 = 'L': apply Q or Q**H from the Left;
 = 'R': apply Q or Q**H from the Right.

UPLO

 UPLO is CHARACTER*1
 = 'U': Upper triangular packed storage used in previous
 call to CHPTRD;
 = 'L': Lower triangular packed storage used in previous
 call to CHPTRD.

TRANS

 TRANS is CHARACTER*1
 = 'N': No transpose, apply Q;
 = 'C': Conjugate transpose, apply Q**H.

M

 M is INTEGER
 The number of rows of the matrix C. M >= 0.

N

 N is INTEGER
 The number of columns of the matrix C. N >= 0.

AP

 AP is COMPLEX 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 CHPTRD. AP is modified by the routine but
 restored on exit.

TAU

 TAU is COMPLEX 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 CHPTRD.

C

 C is COMPLEX array, dimension (LDC,N)
 On entry, the M-by-N matrix C.
 On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q.

LDC

 LDC is INTEGER
 The leading dimension of the array C. LDC >= max(1,M).

WORK

 WORK is COMPLEX array, dimension
 (N) if SIDE = 'L'
 (M) if SIDE = 'R'

INFO

 INFO 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 cupmtr.f.

Author

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