Visible to Intel only — GUID: GUID-694EB0FF-B09B-4399-AA32-F077558E9991
Visible to Intel only — GUID: GUID-694EB0FF-B09B-4399-AA32-F077558E9991
?org2r/?ung2r
Generates all or part of the orthogonal/unitary matrix Q from a QR factorization determined by ?geqrf (unblocked algorithm).
Syntax
call sorg2r( m, n, k, a, lda, tau, work, info )
call dorg2r( m, n, k, a, lda, tau, work, info )
call cung2r( m, n, k, a, lda, tau, work, info )
call zung2r( m, n, k, a, lda, tau, work, info )
Include Files
- mkl.fi
Description
The routine ?org2r/?ung2r generates an m-by-n real/complex 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 ?geqrf.
Input Parameters
- m
-
INTEGER. The number of rows of the matrix Q. m≥ 0.
- n
-
INTEGER. The number of columns of the matrix Q. m≥n≥ 0.
- k
-
INTEGER. The number of elementary reflectors whose product defines the matrix Q. n≥k≥ 0.
- a
-
REAL for sorg2r
DOUBLE PRECISION for dorg2r
COMPLEX for cung2r
DOUBLE COMPLEX for zung2r.
Array, DIMENSION (lda, n).
On entry, the i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,..., k, as returned by ?geqrf in the first k columns of its array argument a.
- lda
-
INTEGER. The first DIMENSION of the array a. lda≥ max(1,m).
- tau
-
REAL for sorg2r
DOUBLE PRECISION for dorg2r
COMPLEX for cung2r
DOUBLE COMPLEX for zung2r.
Array, DIMENSION (k).
tau(i) must contain the scalar factor of the elementary reflector H(i), as returned by ?geqrf.
- work
-
REAL for sorg2r
DOUBLE PRECISION for dorg2r
COMPLEX for cung2r
DOUBLE COMPLEX for zung2r.
Workspace array, DIMENSION (n).
Output Parameters
- a
-
On exit, the m-by-n matrix Q.
- info
-
INTEGER.
= 0: successful exit
< 0: if info = -i, the i-th argument has an illegal value