MAGMA  2.0.0
Matrix Algebra for GPU and Multicore Architectures
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single-complex precision

Functions

magma_int_t magma_cgelqf (magma_int_t m, magma_int_t n, magmaFloatComplex *A, magma_int_t lda, magmaFloatComplex *tau, magmaFloatComplex *work, magma_int_t lwork, magma_int_t *info)
 CGELQF computes an LQ factorization of a COMPLEX M-by-N matrix A: A = L * Q. More...
 
magma_int_t magma_cgelqf_gpu (magma_int_t m, magma_int_t n, magmaFloatComplex_ptr dA, magma_int_t ldda, magmaFloatComplex *tau, magmaFloatComplex *work, magma_int_t lwork, magma_int_t *info)
 CGELQF computes an LQ factorization of a COMPLEX M-by-N matrix dA: dA = L * Q. More...
 
magma_int_t magma_cunglq (magma_int_t m, magma_int_t n, magma_int_t k, magmaFloatComplex *A, magma_int_t lda, magmaFloatComplex *tau, magmaFloatComplex *work, magma_int_t lwork, magma_int_t *info)
 

Purpose:

CUNGLQ generates an M-by-N complex matrix Q with orthonormal rows, which is defined as the first M rows of a product of K elementary reflectors of order N More...
 
magma_int_t magma_cunmlq (magma_side_t side, magma_trans_t trans, magma_int_t m, magma_int_t n, magma_int_t k, magmaFloatComplex *A, magma_int_t lda, magmaFloatComplex *tau, magmaFloatComplex *C, magma_int_t ldc, magmaFloatComplex *work, magma_int_t lwork, magma_int_t *info)
 CUNMLQ overwrites the general complex M-by-N matrix C with. More...
 

Detailed Description

Function Documentation

magma_int_t magma_cgelqf ( magma_int_t  m,
magma_int_t  n,
magmaFloatComplex *  A,
magma_int_t  lda,
magmaFloatComplex *  tau,
magmaFloatComplex *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

CGELQF computes an LQ factorization of a COMPLEX M-by-N matrix A: A = L * Q.

Parameters
[in]mINTEGER The number of rows of the matrix A. M >= 0.
[in]nINTEGER The number of columns of the matrix A. N >= 0.
[in,out]ACOMPLEX array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, the elements on and below the diagonal of the array contain the m-by-min(m,n) lower trapezoidal matrix L (L is lower triangular if m <= n); the elements above the diagonal, with the array TAU, represent the orthogonal matrix Q as a product of elementary reflectors (see Further Details).
Higher performance is achieved if A is in pinned memory, e.g. allocated using magma_malloc_pinned.
[in]ldaINTEGER The leading dimension of the array A. LDA >= max(1,M).
[out]tauCOMPLEX array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details).
[out]work(workspace) COMPLEX array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*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.
TODO: work is currently unused. cgeqrf2 allocates its own work of (m + n)*nb.
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value or another error occured, such as memory allocation failed.

Further Details

The matrix Q is represented as a product of elementary reflectors

Q = H(k) . . . H(2) H(1), where k = min(m,n).

Each H(i) has the form

H(i) = I - tau * v * v'

where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:n) is stored on exit in A(i,i+1:n), and tau in TAU(i).

magma_int_t magma_cgelqf_gpu ( magma_int_t  m,
magma_int_t  n,
magmaFloatComplex_ptr  dA,
magma_int_t  ldda,
magmaFloatComplex *  tau,
magmaFloatComplex *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

CGELQF computes an LQ factorization of a COMPLEX M-by-N matrix dA: dA = L * Q.

Parameters
[in]mINTEGER The number of rows of the matrix A. M >= 0.
[in]nINTEGER The number of columns of the matrix A. N >= 0.
[in,out]dACOMPLEX array on the GPU, dimension (LDDA,N) On entry, the M-by-N matrix dA. On exit, the elements on and below the diagonal of the array contain the m-by-min(m,n) lower trapezoidal matrix L (L is lower triangular if m <= n); the elements above the diagonal, with the array TAU, represent the orthogonal matrix Q as a product of elementary reflectors (see Further Details).
[in]lddaINTEGER The leading dimension of the array dA. LDDA >= max(1,M).
[out]tauCOMPLEX array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details).
[out]work(workspace) COMPLEX array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK.
Higher performance is achieved if WORK is in pinned memory, e.g. allocated using magma_malloc_pinned.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*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.
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value or another error occured, such as memory allocation failed.

Further Details

The matrix Q is represented as a product of elementary reflectors

Q = H(k) . . . H(2) H(1), where k = min(m,n).

Each H(i) has the form

H(i) = I - tau * v * v'

where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:n) is stored on exit in A(i,i+1:n), and tau in TAU(i).

magma_int_t magma_cunglq ( magma_int_t  m,
magma_int_t  n,
magma_int_t  k,
magmaFloatComplex *  A,
magma_int_t  lda,
magmaFloatComplex *  tau,
magmaFloatComplex *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

Purpose:

CUNGLQ generates an M-by-N 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 . . . H(2)**H H(1)**H

as returned by CGELQF.

Arguments:

Parameters
[in]mINTEGER The number of rows of the matrix Q. M >= 0.
[in]nINTEGER The number of columns of the matrix Q. N >= M.
[in]kINTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0.
[in,out]ACOMPLEX 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 CGELQF in the first k rows of its array argument A. On exit, the M-by-N matrix Q.
[in]ldaINTEGER The first dimension of the array A. LDA >= max(1,M).
[in]tauCOMPLEX array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGELQF.
[out]workCOMPLEX array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= NB*NB, where NB is the optimal blocksize.

If LWORK = -1, 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.

Parameters
[out]infoINTEGER
  • = 0: successful exit;
  • < 0: if INFO = -i, the i-th argument had an illegal value
magma_int_t magma_cunmlq ( magma_side_t  side,
magma_trans_t  trans,
magma_int_t  m,
magma_int_t  n,
magma_int_t  k,
magmaFloatComplex *  A,
magma_int_t  lda,
magmaFloatComplex *  tau,
magmaFloatComplex *  C,
magma_int_t  ldc,
magmaFloatComplex *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

CUNMLQ overwrites the general complex M-by-N matrix C with.

                         SIDE = MagmaLeft     SIDE = MagmaRight
TRANS = MagmaNoTrans:    Q * C                C * Q
TRANS = Magma_ConjTrans: Q**H * C             C * Q**H

where Q is a complexunitary matrix defined as the product of k elementary reflectors

  Q = H(k)**H . . . H(2)**H H(1)**H

as returned by CGELQF. Q is of order M if SIDE = MagmaLeft and of order N if SIDE = MagmaRight.

Parameters
[in]sidemagma_side_t
  • = MagmaLeft: apply Q or Q**H from the Left;
  • = MagmaRight: apply Q or Q**H from the Right.
[in]transmagma_trans_t
  • = MagmaNoTrans: No transpose, apply Q;
  • = Magma_ConjTrans: Conjugate transpose, apply Q**H.
[in]mINTEGER The number of rows of the matrix C. M >= 0.
[in]nINTEGER The number of columns of the matrix C. N >= 0.
[in]kINTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = MagmaLeft, M >= K >= 0; if SIDE = MagmaRight, N >= K >= 0.
[in]ACOMPLEX array, dimension (LDA,M) if SIDE = MagmaLeft, (LDA,N) if SIDE = MagmaRight. The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by CGELQF in the first k rows of its array argument A. A is modified by the routine but restored on exit.
[in]ldaINTEGER The leading dimension of the array A. LDA >= max(1,K).
[in]tauCOMPLEX array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGELQF.
[in,out]CCOMPLEX array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q.
[in]ldcINTEGER The leading dimension of the array C. LDC >= max(1,M).
[out]work(workspace) COMPLEX array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK[0] returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. If SIDE = MagmaLeft, LWORK >= max(1,N); if SIDE = MagmaRight, LWORK >= max(1,M). For optimum performance if SIDE = MagmaLeft, LWORK >= N*NB; if SIDE = MagmaRight, LWORK >= M*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.
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value