PLASMA  2.8.0
PLASMA - Parallel Linear Algebra for Scalable Multi-core Architectures
int PLASMA_zgels ( PLASMA_enum  trans,
int  M,
int  N,
int  NRHS,
PLASMA_Complex64_t *  A,
int  LDA,
PLASMA_desc descT,
PLASMA_Complex64_t *  B,
int  LDB 
)

PLASMA_zgels - solves overdetermined or underdetermined linear systems involving an M-by-N matrix A using the QR or the LQ factorization of A. It is assumed that A has full rank. The following options are provided:

trans = PlasmaNoTrans and M >= N: find the least squares solution of an

overdetermined system, i.e., solve the least squares problem: minimize || B - A*X ||.

trans = PlasmaNoTrans and M < N: find the minimum norm solution of an

underdetermined system A * X = B.

Several right hand side vectors B and solution vectors X can be handled in a single call; they are stored as the columns of the M-by-NRHS right hand side matrix B and the N-by-NRHS solution matrix X.

Parameters
[in]transIntended usage: = PlasmaNoTrans: the linear system involves A; = PlasmaConjTrans: the linear system involves A**H. Currently only PlasmaNoTrans is supported.
[in]MThe number of rows of the matrix A. M >= 0.
[in]NThe number of columns of the matrix A. N >= 0.
[in]NRHSThe number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0.
[in,out]AOn entry, the M-by-N matrix A. On exit, if M >= N, A is overwritten by details of its QR factorization as returned by PLASMA_zgeqrf; if M < N, A is overwritten by details of its LQ factorization as returned by PLASMA_zgelqf.
[in]LDAThe leading dimension of the array A. LDA >= max(1,M).
[out]descTOn exit, auxiliary factorization data.
[in,out]BOn entry, the M-by-NRHS matrix B of right hand side vectors, stored columnwise; On exit, if return value = 0, B is overwritten by the solution vectors, stored columnwise: if M >= N, rows 1 to N of B contain the least squares solution vectors; the residual sum of squares for the solution in each column is given by the sum of squares of the modulus of elements N+1 to M in that column; if M < N, rows 1 to N of B contain the minimum norm solution vectors;
[in]LDBThe leading dimension of the array B. LDB >= MAX(1,M,N).
Returns
Return values
PLASMA_SUCCESSsuccessful exit
<0if -i, the i-th argument had an illegal value
See also
PLASMA_zgels_Tile
PLASMA_zgels_Tile_Async
PLASMA_cgels
PLASMA_dgels
PLASMA_sgels