LAPACK
3.4.2
LAPACK: Linear Algebra PACKage

Go to the source code of this file.
Functions/Subroutines  
subroutine  dorg2r (M, N, K, A, LDA, TAU, WORK, INFO) 
DORG2R generates all or part of the orthogonal matrix Q from a QR factorization determined by sgeqrf (unblocked algorithm). 
subroutine dorg2r  (  integer  M, 
integer  N,  
integer  K,  
double precision, dimension( lda, * )  A,  
integer  LDA,  
double precision, dimension( * )  TAU,  
double precision, dimension( * )  WORK,  
integer  INFO  
) 
DORG2R generates all or part of the orthogonal matrix Q from a QR factorization determined by sgeqrf (unblocked algorithm).
Download DORG2R + dependencies [TGZ] [ZIP] [TXT]DORG2R generates an m by n real matrix Q with orthonormal columns, which is defined as the first n columns of a product of k elementary reflectors of order m Q = H(1) H(2) . . . H(k) as returned by DGEQRF.
[in]  M  M is INTEGER The number of rows of the matrix Q. M >= 0. 
[in]  N  N is INTEGER The number of columns of the matrix Q. M >= N >= 0. 
[in]  K  K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0. 
[in,out]  A  A is DOUBLE PRECISION array, dimension (LDA,N) On entry, the ith column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DGEQRF in the first k columns of its array argument A. On exit, the mbyn matrix Q. 
[in]  LDA  LDA is INTEGER The first dimension of the array A. LDA >= max(1,M). 
[in]  TAU  TAU is DOUBLE PRECISION array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEQRF. 
[out]  WORK  WORK is DOUBLE PRECISION array, dimension (N) 
[out]  INFO  INFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument has an illegal value 
Definition at line 115 of file dorg2r.f.