MAGMA  2.3.0
Matrix Algebra for GPU and Multicore Architectures
 All Classes Files Functions Friends Groups Pages
gerfs: Refine solution - no pivoting

Functions

magma_int_t magma_cgerfs_nopiv_gpu (magma_trans_t trans, magma_int_t n, magma_int_t nrhs, magmaFloatComplex_ptr dA, magma_int_t ldda, magmaFloatComplex_ptr dB, magma_int_t lddb, magmaFloatComplex_ptr dX, magma_int_t lddx, magmaFloatComplex_ptr dworkd, magmaFloatComplex_ptr dAF, magma_int_t *iter, magma_int_t *info)
 CGERFS improves the computed solution to a system of linear equations. More...
 
magma_int_t magma_dgerfs_nopiv_gpu (magma_trans_t trans, magma_int_t n, magma_int_t nrhs, magmaDouble_ptr dA, magma_int_t ldda, magmaDouble_ptr dB, magma_int_t lddb, magmaDouble_ptr dX, magma_int_t lddx, magmaDouble_ptr dworkd, magmaDouble_ptr dAF, magma_int_t *iter, magma_int_t *info)
 DGERFS improves the computed solution to a system of linear equations. More...
 
magma_int_t magma_sgerfs_nopiv_gpu (magma_trans_t trans, magma_int_t n, magma_int_t nrhs, magmaFloat_ptr dA, magma_int_t ldda, magmaFloat_ptr dB, magma_int_t lddb, magmaFloat_ptr dX, magma_int_t lddx, magmaFloat_ptr dworkd, magmaFloat_ptr dAF, magma_int_t *iter, magma_int_t *info)
 SGERFS improves the computed solution to a system of linear equations. More...
 
magma_int_t magma_zgerfs_nopiv_gpu (magma_trans_t trans, magma_int_t n, magma_int_t nrhs, magmaDoubleComplex_ptr dA, magma_int_t ldda, magmaDoubleComplex_ptr dB, magma_int_t lddb, magmaDoubleComplex_ptr dX, magma_int_t lddx, magmaDoubleComplex_ptr dworkd, magmaDoubleComplex_ptr dAF, magma_int_t *iter, magma_int_t *info)
 ZGERFS improves the computed solution to a system of linear equations. More...
 

Detailed Description

Function Documentation

magma_int_t magma_cgerfs_nopiv_gpu ( magma_trans_t  trans,
magma_int_t  n,
magma_int_t  nrhs,
magmaFloatComplex_ptr  dA,
magma_int_t  ldda,
magmaFloatComplex_ptr  dB,
magma_int_t  lddb,
magmaFloatComplex_ptr  dX,
magma_int_t  lddx,
magmaFloatComplex_ptr  dworkd,
magmaFloatComplex_ptr  dAF,
magma_int_t *  iter,
magma_int_t *  info 
)

CGERFS improves the computed solution to a system of linear equations.

The iterative refinement process is stopped if ITER > ITERMAX or for all the RHS we have: RNRM < SQRT(n)*XNRM*ANRM*EPS*BWDMAX where o ITER is the number of the current iteration in the iterative refinement process o RNRM is the infinity-norm of the residual o XNRM is the infinity-norm of the solution o ANRM is the infinity-operator-norm of the matrix A o EPS is the machine epsilon returned by SLAMCH('Epsilon') The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

Parameters
[in]transmagma_trans_t Specifies the form of the system of equations:
  • = MagmaNoTrans: A * X = B (No transpose)
  • = MagmaTrans: A**T * X = B (Transpose)
  • = MagmaConjTrans: A**H * X = B (Conjugate transpose)
[in]nINTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0.
[in]nrhsINTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
[in]dACOMPLEX array on the GPU, dimension (ldda,N) the N-by-N coefficient matrix A.
[in]lddaINTEGER The leading dimension of the array dA. ldda >= max(1,N).
[in]dBCOMPLEX array on the GPU, dimension (lddb,NRHS) The N-by-NRHS right hand side matrix B.
[in]lddbINTEGER The leading dimension of the array dB. lddb >= max(1,N).
[in,out]dXCOMPLEX array on the GPU, dimension (lddx,NRHS) On entry, the solution matrix X, as computed by CGETRS_NOPIV. On exit, the improved solution matrix X.
[in]lddxINTEGER The leading dimension of the array dX. lddx >= max(1,N).
dworkd(workspace) COMPLEX array on the GPU, dimension (N*NRHS) This array is used to hold the residual vectors.
dAFCOMPLEX array on the GPU, dimension (ldda,n) The factors L and U from the factorization A = L*U as computed by CGETRF_NOPIV.
[out]iterINTEGER
  • < 0: iterative refinement has failed, real factorization has been performed
    • -1 : the routine fell back to full precision for implementation- or machine-specific reasons
    • -2 : narrowing the precision induced an overflow, the routine fell back to full precision
    • -3 : failure of SGETRF
    • -31: stop the iterative refinement after the 30th iteration
  • > 0: iterative refinement has been successfully used. Returns the number of iterations
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if info = -i, the i-th argument had an illegal value
  • > 0: if info = i, U(i,i) computed in REAL is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed.
magma_int_t magma_dgerfs_nopiv_gpu ( magma_trans_t  trans,
magma_int_t  n,
magma_int_t  nrhs,
magmaDouble_ptr  dA,
magma_int_t  ldda,
magmaDouble_ptr  dB,
magma_int_t  lddb,
magmaDouble_ptr  dX,
magma_int_t  lddx,
magmaDouble_ptr  dworkd,
magmaDouble_ptr  dAF,
magma_int_t *  iter,
magma_int_t *  info 
)

DGERFS improves the computed solution to a system of linear equations.

The iterative refinement process is stopped if ITER > ITERMAX or for all the RHS we have: RNRM < SQRT(n)*XNRM*ANRM*EPS*BWDMAX where o ITER is the number of the current iteration in the iterative refinement process o RNRM is the infinity-norm of the residual o XNRM is the infinity-norm of the solution o ANRM is the infinity-operator-norm of the matrix A o EPS is the machine epsilon returned by DLAMCH('Epsilon') The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

Parameters
[in]transmagma_trans_t Specifies the form of the system of equations:
  • = MagmaNoTrans: A * X = B (No transpose)
  • = MagmaTrans: A**T * X = B (Transpose)
  • = MagmaConjTrans: A**H * X = B (Conjugate transpose)
[in]nINTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0.
[in]nrhsINTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
[in]dADOUBLE PRECISION array on the GPU, dimension (ldda,N) the N-by-N coefficient matrix A.
[in]lddaINTEGER The leading dimension of the array dA. ldda >= max(1,N).
[in]dBDOUBLE PRECISION array on the GPU, dimension (lddb,NRHS) The N-by-NRHS right hand side matrix B.
[in]lddbINTEGER The leading dimension of the array dB. lddb >= max(1,N).
[in,out]dXDOUBLE PRECISION array on the GPU, dimension (lddx,NRHS) On entry, the solution matrix X, as computed by DGETRS_NOPIV. On exit, the improved solution matrix X.
[in]lddxINTEGER The leading dimension of the array dX. lddx >= max(1,N).
dworkd(workspace) DOUBLE PRECISION array on the GPU, dimension (N*NRHS) This array is used to hold the residual vectors.
dAFDOUBLE PRECISION array on the GPU, dimension (ldda,n) The factors L and U from the factorization A = L*U as computed by DGETRF_NOPIV.
[out]iterINTEGER
  • < 0: iterative refinement has failed, double precision factorization has been performed
    • -1 : the routine fell back to full precision for implementation- or machine-specific reasons
    • -2 : narrowing the precision induced an overflow, the routine fell back to full precision
    • -3 : failure of SGETRF
    • -31: stop the iterative refinement after the 30th iteration
  • > 0: iterative refinement has been successfully used. Returns the number of iterations
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if info = -i, the i-th argument had an illegal value
  • > 0: if info = i, U(i,i) computed in DOUBLE PRECISION is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed.
magma_int_t magma_sgerfs_nopiv_gpu ( magma_trans_t  trans,
magma_int_t  n,
magma_int_t  nrhs,
magmaFloat_ptr  dA,
magma_int_t  ldda,
magmaFloat_ptr  dB,
magma_int_t  lddb,
magmaFloat_ptr  dX,
magma_int_t  lddx,
magmaFloat_ptr  dworkd,
magmaFloat_ptr  dAF,
magma_int_t *  iter,
magma_int_t *  info 
)

SGERFS improves the computed solution to a system of linear equations.

The iterative refinement process is stopped if ITER > ITERMAX or for all the RHS we have: RNRM < SQRT(n)*XNRM*ANRM*EPS*BWDMAX where o ITER is the number of the current iteration in the iterative refinement process o RNRM is the infinity-norm of the residual o XNRM is the infinity-norm of the solution o ANRM is the infinity-operator-norm of the matrix A o EPS is the machine epsilon returned by SLAMCH('Epsilon') The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

Parameters
[in]transmagma_trans_t Specifies the form of the system of equations:
  • = MagmaNoTrans: A * X = B (No transpose)
  • = MagmaTrans: A**T * X = B (Transpose)
  • = MagmaConjTrans: A**H * X = B (Conjugate transpose)
[in]nINTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0.
[in]nrhsINTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
[in]dAREAL array on the GPU, dimension (ldda,N) the N-by-N coefficient matrix A.
[in]lddaINTEGER The leading dimension of the array dA. ldda >= max(1,N).
[in]dBREAL array on the GPU, dimension (lddb,NRHS) The N-by-NRHS right hand side matrix B.
[in]lddbINTEGER The leading dimension of the array dB. lddb >= max(1,N).
[in,out]dXREAL array on the GPU, dimension (lddx,NRHS) On entry, the solution matrix X, as computed by SGETRS_NOPIV. On exit, the improved solution matrix X.
[in]lddxINTEGER The leading dimension of the array dX. lddx >= max(1,N).
dworkd(workspace) REAL array on the GPU, dimension (N*NRHS) This array is used to hold the residual vectors.
dAFREAL array on the GPU, dimension (ldda,n) The factors L and U from the factorization A = L*U as computed by SGETRF_NOPIV.
[out]iterINTEGER
  • < 0: iterative refinement has failed, real factorization has been performed
    • -1 : the routine fell back to full precision for implementation- or machine-specific reasons
    • -2 : narrowing the precision induced an overflow, the routine fell back to full precision
    • -3 : failure of SGETRF
    • -31: stop the iterative refinement after the 30th iteration
  • > 0: iterative refinement has been successfully used. Returns the number of iterations
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if info = -i, the i-th argument had an illegal value
  • > 0: if info = i, U(i,i) computed in REAL is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed.
magma_int_t magma_zgerfs_nopiv_gpu ( magma_trans_t  trans,
magma_int_t  n,
magma_int_t  nrhs,
magmaDoubleComplex_ptr  dA,
magma_int_t  ldda,
magmaDoubleComplex_ptr  dB,
magma_int_t  lddb,
magmaDoubleComplex_ptr  dX,
magma_int_t  lddx,
magmaDoubleComplex_ptr  dworkd,
magmaDoubleComplex_ptr  dAF,
magma_int_t *  iter,
magma_int_t *  info 
)

ZGERFS improves the computed solution to a system of linear equations.

The iterative refinement process is stopped if ITER > ITERMAX or for all the RHS we have: RNRM < SQRT(n)*XNRM*ANRM*EPS*BWDMAX where o ITER is the number of the current iteration in the iterative refinement process o RNRM is the infinity-norm of the residual o XNRM is the infinity-norm of the solution o ANRM is the infinity-operator-norm of the matrix A o EPS is the machine epsilon returned by DLAMCH('Epsilon') The value ITERMAX and BWDMAX are fixed to 30 and 1.0D+00 respectively.

Parameters
[in]transmagma_trans_t Specifies the form of the system of equations:
  • = MagmaNoTrans: A * X = B (No transpose)
  • = MagmaTrans: A**T * X = B (Transpose)
  • = MagmaConjTrans: A**H * X = B (Conjugate transpose)
[in]nINTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0.
[in]nrhsINTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
[in]dACOMPLEX_16 array on the GPU, dimension (ldda,N) the N-by-N coefficient matrix A.
[in]lddaINTEGER The leading dimension of the array dA. ldda >= max(1,N).
[in]dBCOMPLEX_16 array on the GPU, dimension (lddb,NRHS) The N-by-NRHS right hand side matrix B.
[in]lddbINTEGER The leading dimension of the array dB. lddb >= max(1,N).
[in,out]dXCOMPLEX_16 array on the GPU, dimension (lddx,NRHS) On entry, the solution matrix X, as computed by ZGETRS_NOPIV. On exit, the improved solution matrix X.
[in]lddxINTEGER The leading dimension of the array dX. lddx >= max(1,N).
dworkd(workspace) COMPLEX_16 array on the GPU, dimension (N*NRHS) This array is used to hold the residual vectors.
dAFCOMPLEX*16 array on the GPU, dimension (ldda,n) The factors L and U from the factorization A = L*U as computed by ZGETRF_NOPIV.
[out]iterINTEGER
  • < 0: iterative refinement has failed, double precision factorization has been performed
    • -1 : the routine fell back to full precision for implementation- or machine-specific reasons
    • -2 : narrowing the precision induced an overflow, the routine fell back to full precision
    • -3 : failure of SGETRF
    • -31: stop the iterative refinement after the 30th iteration
  • > 0: iterative refinement has been successfully used. Returns the number of iterations
[out]infoINTEGER
  • = 0: successful exit
  • < 0: if info = -i, the i-th argument had an illegal value
  • > 0: if info = i, U(i,i) computed in DOUBLE PRECISION is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed.