LAPACK  3.4.2
LAPACK: Linear Algebra PACKage
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cupgtr.f File Reference

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subroutine cupgtr (UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

Function/Subroutine Documentation

subroutine cupgtr ( character  UPLO,
integer  N,
complex, dimension( * )  AP,
complex, dimension( * )  TAU,
complex, dimension( ldq, * )  Q,
integer  LDQ,
complex, dimension( * )  WORK,
integer  INFO 


Download CUPGTR + dependencies [TGZ] [ZIP] [TXT]
 CUPGTR generates a complex unitary matrix Q which is defined as the
 product of n-1 elementary reflectors H(i) of order n, as returned by
 CHPTRD using packed storage:

 if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),

 if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).
          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.
          N is INTEGER
          The order of the matrix Q. N >= 0.
          AP is COMPLEX array, dimension (N*(N+1)/2)
          The vectors which define the elementary reflectors, as
          returned by CHPTRD.
          TAU is COMPLEX array, dimension (N-1)
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by CHPTRD.
          Q is COMPLEX array, dimension (LDQ,N)
          The N-by-N unitary matrix Q.
          LDQ is INTEGER
          The leading dimension of the array Q. LDQ >= max(1,N).
          WORK is COMPLEX array, dimension (N-1)
          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
November 2011

Definition at line 115 of file cupgtr.f.

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