LAPACK
3.4.2
LAPACK: Linear Algebra PACKage

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Functions/Subroutines  
subroutine  dopgtr (UPLO, N, AP, TAU, Q, LDQ, WORK, INFO) 
DOPGTR 
subroutine dopgtr  (  character  UPLO, 
integer  N,  
double precision, dimension( * )  AP,  
double precision, dimension( * )  TAU,  
double precision, dimension( ldq, * )  Q,  
integer  LDQ,  
double precision, dimension( * )  WORK,  
integer  INFO  
) 
DOPGTR
Download DOPGTR + dependencies [TGZ] [ZIP] [TXT]DOPGTR generates a real orthogonal matrix Q which is defined as the product of n1 elementary reflectors H(i) of order n, as returned by DSPTRD using packed storage: if UPLO = 'U', Q = H(n1) . . . H(2) H(1), if UPLO = 'L', Q = H(1) H(2) . . . H(n1).
[in]  UPLO  UPLO 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. 
[in]  N  N is INTEGER The order of the matrix Q. N >= 0. 
[in]  AP  AP is DOUBLE PRECISION array, dimension (N*(N+1)/2) The vectors which define the elementary reflectors, as returned by DSPTRD. 
[in]  TAU  TAU is DOUBLE PRECISION array, dimension (N1) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DSPTRD. 
[out]  Q  Q is DOUBLE PRECISION array, dimension (LDQ,N) The NbyN orthogonal matrix Q. 
[in]  LDQ  LDQ is INTEGER The leading dimension of the array Q. LDQ >= max(1,N). 
[out]  WORK  WORK is DOUBLE PRECISION array, dimension (N1) 
[out]  INFO  INFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value 
Definition at line 115 of file dopgtr.f.