Visible to Intel only — GUID: GUID-07C2C34F-E348-4EB9-B5AE-4BAF897D5A7D
Visible to Intel only — GUID: GUID-07C2C34F-E348-4EB9-B5AE-4BAF897D5A7D
?orgl2/?ungl2
Generates all or part of the orthogonal/unitary matrix Q from an LQ factorization determined by ?gelqf (unblocked algorithm).
Syntax
call sorgl2( m, n, k, a, lda, tau, work, info )
call dorgl2( m, n, k, a, lda, tau, work, info )
call cungl2( m, n, k, a, lda, tau, work, info )
call zungl2( m, n, k, a, lda, tau, work, info )
Include Files
- mkl.fi
Description
The routine ?orgl2/?ungl2 generates a m-by-n real/complex matrix Q with orthonormal rows, which is defined as the first m rows of a product of k elementary reflectors of order n
Q = H(k)*...*H(2)*H(1)for real flavors, or Q = (H(k))H*...*(H(2))H*(H(1))H for complex flavors as returned by ?gelqf.
Input Parameters
- m
-
INTEGER. The number of rows of the matrix Q. m≥ 0.
- n
-
INTEGER. The number of columns of the matrix Q. n≥m.
- k
-
INTEGER. The number of elementary reflectors whose product defines the matrix Q. m≥k≥ 0.
- a
-
REAL for sorgl2
DOUBLE PRECISION for dorgl2
COMPLEX for cungl2
DOUBLE COMPLEX for zungl2.
Array, DIMENSION (lda, n). On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,..., k, as returned by ?gelqf in the first k rows of its array argument a.
- lda
-
INTEGER. The leading dimension of the array a. lda≥ max(1,m).
- tau
-
REAL for sorgl2
DOUBLE PRECISION for dorgl2
COMPLEX for cungl2
DOUBLE COMPLEX for zungl2.
Array, DIMENSION (k).
tau(i) must contain the scalar factor of the elementary reflector H(i), as returned by ?gelqf.
- work
-
REAL for sorgl2
DOUBLE PRECISION for dorgl2
COMPLEX for cungl2
DOUBLE COMPLEX for zungl2.
Workspace array, DIMENSION (m).
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.