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DORGQRRun Method

Purpose ======= DORGQR 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.

Namespace: DotNumerics.LinearAlgebra.CSLapack
Assembly: DWSIM.MathOps.DotNumerics (in DWSIM.MathOps.DotNumerics.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax
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public void Run(
	int M,
	int N,
	int K,
	ref double[] A,
	int offset_a,
	int LDA,
	double[] TAU,
	int offset_tau,
	ref double[] WORK,
	int offset_work,
	int LWORK,
	ref int INFO
)
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Parameters

M  Int32
(input) INTEGER The number of rows of the matrix Q. M .GE. 0.
N  Int32
(input) INTEGER The number of columns of the matrix Q. M .GE. N .GE. 0.
K  Int32
(input) INTEGER The number of elementary reflectors whose product defines the matrix Q. N .GE. K .GE. 0.
A  Double
(input/output) DOUBLE PRECISION 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 DGEQRF in the first k columns of its array argument A. On exit, the M-by-N matrix Q.
offset_a  Int32
 
LDA  Int32
(input) INTEGER The first dimension of the array A. LDA .GE. max(1,M).
TAU  Double
(input) DOUBLE PRECISION array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEQRF.
offset_tau  Int32
 
WORK  Double
(workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
offset_work  Int32
 
LWORK  Int32
(input) INTEGER The dimension of the array WORK. LWORK .GE. max(1,N). For optimum performance LWORK .GE. N*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.
INFO  Int32
(output) INTEGER = 0: successful exit .LT. 0: if INFO = -i, the i-th argument has an illegal value
See Also