ungql - Man Page
{un,or}gql: generate explicit Q from geqlf
Synopsis
Functions
subroutine cungql (m, n, k, a, lda, tau, work, lwork, info)
CUNGQL
subroutine dorgql (m, n, k, a, lda, tau, work, lwork, info)
DORGQL
subroutine sorgql (m, n, k, a, lda, tau, work, lwork, info)
SORGQL
subroutine zungql (m, n, k, a, lda, tau, work, lwork, info)
ZUNGQL
Detailed Description
Function Documentation
subroutine cungql (integer m, integer n, integer k, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tau, complex, dimension( * ) work, integer lwork, integer info)
CUNGQL
Purpose:
CUNGQL generates an M-by-N complex matrix Q with orthonormal columns,
which is defined as the last N columns of a product of K elementary
reflectors of order M
Q = H(k) . . . H(2) H(1)
as returned by CGEQLF.- Parameters
M
M is INTEGER The number of rows of the matrix Q. M >= 0.N
N is INTEGER The number of columns of the matrix Q. M >= N >= 0.K
K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.A
A is COMPLEX array, dimension (LDA,N) On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by CGEQLF in the last k columns of its array argument A. On exit, the M-by-N matrix Q.LDA
LDA is INTEGER The first dimension of the array A. LDA >= max(1,M).TAU
TAU is COMPLEX array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGEQLF.WORK
WORK is COMPLEX array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.LWORK
LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= 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
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 127 of file cungql.f.
subroutine dorgql (integer m, integer n, integer k, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) tau, double precision, dimension( * ) work, integer lwork, integer info)
DORGQL
Purpose:
DORGQL generates an M-by-N real matrix Q with orthonormal columns,
which is defined as the last N columns of a product of K elementary
reflectors of order M
Q = H(k) . . . H(2) H(1)
as returned by DGEQLF.- Parameters
M
M is INTEGER The number of rows of the matrix Q. M >= 0.N
N is INTEGER The number of columns of the matrix Q. M >= N >= 0.K
K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.A
A is DOUBLE PRECISION array, dimension (LDA,N) On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DGEQLF in the last k columns of its array argument A. On exit, the M-by-N matrix Q.LDA
LDA is INTEGER The first dimension of the array A. LDA >= max(1,M).TAU
TAU is DOUBLE PRECISION array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEQLF.WORK
WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.LWORK
LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= 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
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 127 of file dorgql.f.
subroutine sorgql (integer m, integer n, integer k, real, dimension( lda, * ) a, integer lda, real, dimension( * ) tau, real, dimension( * ) work, integer lwork, integer info)
SORGQL
Purpose:
SORGQL generates an M-by-N real matrix Q with orthonormal columns,
which is defined as the last N columns of a product of K elementary
reflectors of order M
Q = H(k) . . . H(2) H(1)
as returned by SGEQLF.- Parameters
M
M is INTEGER The number of rows of the matrix Q. M >= 0.N
N is INTEGER The number of columns of the matrix Q. M >= N >= 0.K
K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.A
A is REAL array, dimension (LDA,N) On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by SGEQLF in the last k columns of its array argument A. On exit, the M-by-N matrix Q.LDA
LDA is INTEGER The first dimension of the array A. LDA >= max(1,M).TAU
TAU is REAL array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SGEQLF.WORK
WORK is REAL array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.LWORK
LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= 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
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 127 of file sorgql.f.
subroutine zungql (integer m, integer n, integer k, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16, dimension( * ) work, integer lwork, integer info)
ZUNGQL
Purpose:
ZUNGQL generates an M-by-N complex matrix Q with orthonormal columns,
which is defined as the last N columns of a product of K elementary
reflectors of order M
Q = H(k) . . . H(2) H(1)
as returned by ZGEQLF.- Parameters
M
M is INTEGER The number of rows of the matrix Q. M >= 0.N
N is INTEGER The number of columns of the matrix Q. M >= N >= 0.K
K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.A
A is COMPLEX*16 array, dimension (LDA,N) On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQLF in the last k columns of its array argument A. On exit, the M-by-N matrix Q.LDA
LDA is INTEGER The first dimension of the array A. LDA >= max(1,M).TAU
TAU is COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQLF.WORK
WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.LWORK
LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= 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
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 127 of file zungql.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Info
Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK