MAGMA  2.7.1
Matrix Algebra for GPU and Multicore Architectures
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ggrqf: generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B

Functions

magma_int_t magma_cggrqf (magma_int_t m, magma_int_t p, magma_int_t n, magmaFloatComplex *A, magma_int_t lda, magmaFloatComplex *taua, magmaFloatComplex *B, magma_int_t ldb, magmaFloatComplex *taub, magmaFloatComplex *work, magma_int_t lwork, magma_int_t *info)
 CGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B: More...
 
magma_int_t magma_dggrqf (magma_int_t m, magma_int_t p, magma_int_t n, double *A, magma_int_t lda, double *taua, double *B, magma_int_t ldb, double *taub, double *work, magma_int_t lwork, magma_int_t *info)
 DGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B: More...
 
magma_int_t magma_sggrqf (magma_int_t m, magma_int_t p, magma_int_t n, float *A, magma_int_t lda, float *taua, float *B, magma_int_t ldb, float *taub, float *work, magma_int_t lwork, magma_int_t *info)
 SGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B: More...
 
magma_int_t magma_zggrqf (magma_int_t m, magma_int_t p, magma_int_t n, magmaDoubleComplex *A, magma_int_t lda, magmaDoubleComplex *taua, magmaDoubleComplex *B, magma_int_t ldb, magmaDoubleComplex *taub, magmaDoubleComplex *work, magma_int_t lwork, magma_int_t *info)
 ZGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B: More...
 

Detailed Description

Function Documentation

magma_int_t magma_cggrqf ( magma_int_t  m,
magma_int_t  p,
magma_int_t  n,
magmaFloatComplex *  A,
magma_int_t  lda,
magmaFloatComplex *  taua,
magmaFloatComplex *  B,
magma_int_t  ldb,
magmaFloatComplex *  taub,
magmaFloatComplex *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

CGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B:

        A = R*Q,        B = Z*T*Q,   

where Q is an N-by-N unitary matrix, Z is a P-by-P unitary matrix, and R and T assume one of the forms:

if M <= N, R = ( 0 R12 ) M, or if M > N, R = ( R11 ) M-N, N-M M ( R21 ) N N

where R12 or R21 is upper triangular, and

if P >= N, T = ( T11 ) N , or if P < N, T = ( T11 T12 ) P, ( 0 ) P-N P N-P N

where T11 is upper triangular.

In particular, if B is square and nonsingular, the GRQ factorization of A and B implicitly gives the RQ factorization of A*inv(B):

         A*inv(B) = (R*inv(T))*Z'   

where inv(B) denotes the inverse of the matrix B, and Z' denotes the conjugate transpose of the matrix Z.

Parameters
[in]mINTEGER The number of rows of the matrix A. M >= 0.
[in]pINTEGER The number of rows of the matrix B. P >= 0.
[in]nINTEGER The number of columns of the matrices A and B. N >= 0.
[in,out]ACOMPLEX array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, if M <= N, the upper triangle of the subarray A(1:M,N-M+1:N) contains the M-by-M upper triangular matrix R; if M > N, the elements on and above the (M-N)-th subdiagonal contain the M-by-N upper trapezoidal matrix R; the remaining elements, with the array TAUA, represent the unitary matrix Q as a product of elementary reflectors (see Further Details).
[in]ldaINTEGER The leading dimension of the array A. LDA >= max(1,M).
[out]tauaCOMPLEX array, dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the unitary matrix Q (see Further Details).
[in,out]BCOMPLEX array, dimension (LDB,N) On entry, the P-by-N matrix B. On exit, the elements on and above the diagonal of the array contain the min(P,N)-by-N upper trapezoidal matrix T (T is upper triangular if P >= N); the elements below the diagonal, with the array TAUB, represent the unitary matrix Z as a product of elementary reflectors (see Further Details).
[in]ldbINTEGER The leading dimension of the array B. LDB >= max(1,P).
[out]taubCOMPLEX array, dimension (min(P,N)) The scalar factors of the elementary reflectors which represent the unitary matrix Z (see Further Details).
[out]work(workspace) COMPLEX array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= max(1,N,M,P). For optimum performance LWORK >= max(N,M,P)*NB, where NB is the optimal blocksize for the QR factorization of a P-by-N matrix.
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.

Further Details

The matrix Q is represented as a product of elementary reflectors

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

Each H(i) has the form

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

where taua is a complex scalar, and v is a complex vector with v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in A(m-k+i,1:n-k+i-1), and taua in TAUA(i). To form Q explicitly, use LAPACK subroutine ZUNGRQ. To use Q to update another matrix, use LAPACK subroutine CUNMRQ.

The matrix Z is represented as a product of elementary reflectors

Z = H(1) H(2) . . . H(k), where k = min(p,n).

Each H(i) has the form

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

where taub is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:p) is stored on exit in B(i+1:p,i), and taub in TAUB(i). To form Z explicitly, use LAPACK subroutine CUNGQR. To use Z to update another matrix, use LAPACK subroutine CUNMQR.

magma_int_t magma_dggrqf ( magma_int_t  m,
magma_int_t  p,
magma_int_t  n,
double *  A,
magma_int_t  lda,
double *  taua,
double *  B,
magma_int_t  ldb,
double *  taub,
double *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

DGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B:

        A = R*Q,        B = Z*T*Q,   

where Q is an N-by-N orthogonal matrix, Z is a P-by-P orthogonal matrix, and R and T assume one of the forms:

if M <= N, R = ( 0 R12 ) M, or if M > N, R = ( R11 ) M-N, N-M M ( R21 ) N N

where R12 or R21 is upper triangular, and

if P >= N, T = ( T11 ) N , or if P < N, T = ( T11 T12 ) P, ( 0 ) P-N P N-P N

where T11 is upper triangular.

In particular, if B is square and nonsingular, the GRQ factorization of A and B implicitly gives the RQ factorization of A*inv(B):

         A*inv(B) = (R*inv(T))*Z'   

where inv(B) denotes the inverse of the matrix B, and Z' denotes the conjugate transpose of the matrix Z.

Parameters
[in]mINTEGER The number of rows of the matrix A. M >= 0.
[in]pINTEGER The number of rows of the matrix B. P >= 0.
[in]nINTEGER The number of columns of the matrices A and B. N >= 0.
[in,out]ADOUBLE PRECISION array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, if M <= N, the upper triangle of the subarray A(1:M,N-M+1:N) contains the M-by-M upper triangular matrix R; if M > N, the elements on and above the (M-N)-th subdiagonal contain the M-by-N upper trapezoidal matrix R; the remaining elements, with the array TAUA, represent the orthogonal matrix Q as a product of elementary reflectors (see Further Details).
[in]ldaINTEGER The leading dimension of the array A. LDA >= max(1,M).
[out]tauaDOUBLE PRECISION array, dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the orthogonal matrix Q (see Further Details).
[in,out]BDOUBLE PRECISION array, dimension (LDB,N) On entry, the P-by-N matrix B. On exit, the elements on and above the diagonal of the array contain the min(P,N)-by-N upper trapezoidal matrix T (T is upper triangular if P >= N); the elements below the diagonal, with the array TAUB, represent the orthogonal matrix Z as a product of elementary reflectors (see Further Details).
[in]ldbINTEGER The leading dimension of the array B. LDB >= max(1,P).
[out]taubDOUBLE PRECISION array, dimension (min(P,N)) The scalar factors of the elementary reflectors which represent the orthogonal matrix Z (see Further Details).
[out]work(workspace) DOUBLE PRECISION array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= max(1,N,M,P). For optimum performance LWORK >= max(N,M,P)*NB, where NB is the optimal blocksize for the QR factorization of a P-by-N matrix.
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.

Further Details

The matrix Q is represented as a product of elementary reflectors

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

Each H(i) has the form

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

where taua is a real scalar, and v is a real vector with v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in A(m-k+i,1:n-k+i-1), and taua in TAUA(i). To form Q explicitly, use LAPACK subroutine ZUNGRQ. To use Q to update another matrix, use LAPACK subroutine DORMRQ.

The matrix Z is represented as a product of elementary reflectors

Z = H(1) H(2) . . . H(k), where k = min(p,n).

Each H(i) has the form

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

where taub is a real scalar, and v is a real vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:p) is stored on exit in B(i+1:p,i), and taub in TAUB(i). To form Z explicitly, use LAPACK subroutine DORGQR. To use Z to update another matrix, use LAPACK subroutine DORMQR.

magma_int_t magma_sggrqf ( magma_int_t  m,
magma_int_t  p,
magma_int_t  n,
float *  A,
magma_int_t  lda,
float *  taua,
float *  B,
magma_int_t  ldb,
float *  taub,
float *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

SGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B:

        A = R*Q,        B = Z*T*Q,   

where Q is an N-by-N orthogonal matrix, Z is a P-by-P orthogonal matrix, and R and T assume one of the forms:

if M <= N, R = ( 0 R12 ) M, or if M > N, R = ( R11 ) M-N, N-M M ( R21 ) N N

where R12 or R21 is upper triangular, and

if P >= N, T = ( T11 ) N , or if P < N, T = ( T11 T12 ) P, ( 0 ) P-N P N-P N

where T11 is upper triangular.

In particular, if B is square and nonsingular, the GRQ factorization of A and B implicitly gives the RQ factorization of A*inv(B):

         A*inv(B) = (R*inv(T))*Z'   

where inv(B) denotes the inverse of the matrix B, and Z' denotes the conjugate transpose of the matrix Z.

Parameters
[in]mINTEGER The number of rows of the matrix A. M >= 0.
[in]pINTEGER The number of rows of the matrix B. P >= 0.
[in]nINTEGER The number of columns of the matrices A and B. N >= 0.
[in,out]AREAL array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, if M <= N, the upper triangle of the subarray A(1:M,N-M+1:N) contains the M-by-M upper triangular matrix R; if M > N, the elements on and above the (M-N)-th subdiagonal contain the M-by-N upper trapezoidal matrix R; the remaining elements, with the array TAUA, represent the orthogonal matrix Q as a product of elementary reflectors (see Further Details).
[in]ldaINTEGER The leading dimension of the array A. LDA >= max(1,M).
[out]tauaREAL array, dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the orthogonal matrix Q (see Further Details).
[in,out]BREAL array, dimension (LDB,N) On entry, the P-by-N matrix B. On exit, the elements on and above the diagonal of the array contain the min(P,N)-by-N upper trapezoidal matrix T (T is upper triangular if P >= N); the elements below the diagonal, with the array TAUB, represent the orthogonal matrix Z as a product of elementary reflectors (see Further Details).
[in]ldbINTEGER The leading dimension of the array B. LDB >= max(1,P).
[out]taubREAL array, dimension (min(P,N)) The scalar factors of the elementary reflectors which represent the orthogonal matrix Z (see Further Details).
[out]work(workspace) REAL array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= max(1,N,M,P). For optimum performance LWORK >= max(N,M,P)*NB, where NB is the optimal blocksize for the QR factorization of a P-by-N matrix.
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.

Further Details

The matrix Q is represented as a product of elementary reflectors

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

Each H(i) has the form

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

where taua is a real scalar, and v is a real vector with v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in A(m-k+i,1:n-k+i-1), and taua in TAUA(i). To form Q explicitly, use LAPACK subroutine ZUNGRQ. To use Q to update another matrix, use LAPACK subroutine SORMRQ.

The matrix Z is represented as a product of elementary reflectors

Z = H(1) H(2) . . . H(k), where k = min(p,n).

Each H(i) has the form

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

where taub is a real scalar, and v is a real vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:p) is stored on exit in B(i+1:p,i), and taub in TAUB(i). To form Z explicitly, use LAPACK subroutine SORGQR. To use Z to update another matrix, use LAPACK subroutine SORMQR.

magma_int_t magma_zggrqf ( magma_int_t  m,
magma_int_t  p,
magma_int_t  n,
magmaDoubleComplex *  A,
magma_int_t  lda,
magmaDoubleComplex *  taua,
magmaDoubleComplex *  B,
magma_int_t  ldb,
magmaDoubleComplex *  taub,
magmaDoubleComplex *  work,
magma_int_t  lwork,
magma_int_t *  info 
)

ZGGRQF computes a generalized RQ factorization of an M-by-N matrix A and a P-by-N matrix B:

        A = R*Q,        B = Z*T*Q,   

where Q is an N-by-N unitary matrix, Z is a P-by-P unitary matrix, and R and T assume one of the forms:

if M <= N, R = ( 0 R12 ) M, or if M > N, R = ( R11 ) M-N, N-M M ( R21 ) N N

where R12 or R21 is upper triangular, and

if P >= N, T = ( T11 ) N , or if P < N, T = ( T11 T12 ) P, ( 0 ) P-N P N-P N

where T11 is upper triangular.

In particular, if B is square and nonsingular, the GRQ factorization of A and B implicitly gives the RQ factorization of A*inv(B):

         A*inv(B) = (R*inv(T))*Z'   

where inv(B) denotes the inverse of the matrix B, and Z' denotes the conjugate transpose of the matrix Z.

Parameters
[in]mINTEGER The number of rows of the matrix A. M >= 0.
[in]pINTEGER The number of rows of the matrix B. P >= 0.
[in]nINTEGER The number of columns of the matrices A and B. N >= 0.
[in,out]ACOMPLEX_16 array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, if M <= N, the upper triangle of the subarray A(1:M,N-M+1:N) contains the M-by-M upper triangular matrix R; if M > N, the elements on and above the (M-N)-th subdiagonal contain the M-by-N upper trapezoidal matrix R; the remaining elements, with the array TAUA, represent the unitary matrix Q as a product of elementary reflectors (see Further Details).
[in]ldaINTEGER The leading dimension of the array A. LDA >= max(1,M).
[out]tauaCOMPLEX_16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the unitary matrix Q (see Further Details).
[in,out]BCOMPLEX_16 array, dimension (LDB,N) On entry, the P-by-N matrix B. On exit, the elements on and above the diagonal of the array contain the min(P,N)-by-N upper trapezoidal matrix T (T is upper triangular if P >= N); the elements below the diagonal, with the array TAUB, represent the unitary matrix Z as a product of elementary reflectors (see Further Details).
[in]ldbINTEGER The leading dimension of the array B. LDB >= max(1,P).
[out]taubCOMPLEX_16 array, dimension (min(P,N)) The scalar factors of the elementary reflectors which represent the unitary matrix Z (see Further Details).
[out]work(workspace) COMPLEX_16 array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
[in]lworkINTEGER The dimension of the array WORK. LWORK >= max(1,N,M,P). For optimum performance LWORK >= max(N,M,P)*NB, where NB is the optimal blocksize for the QR factorization of a P-by-N matrix.
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.

Further Details

The matrix Q is represented as a product of elementary reflectors

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

Each H(i) has the form

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

where taua is a complex scalar, and v is a complex vector with v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in A(m-k+i,1:n-k+i-1), and taua in TAUA(i). To form Q explicitly, use LAPACK subroutine ZUNGRQ. To use Q to update another matrix, use LAPACK subroutine ZUNMRQ.

The matrix Z is represented as a product of elementary reflectors

Z = H(1) H(2) . . . H(k), where k = min(p,n).

Each H(i) has the form

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

where taub is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:p) is stored on exit in B(i+1:p,i), and taub in TAUB(i). To form Z explicitly, use LAPACK subroutine ZUNGQR. To use Z to update another matrix, use LAPACK subroutine ZUNMQR.