C++ (Cpp) MAGMA_D_SUB Exemples

Exemple #1

Fichier : testing_dgetrf_gpu.cpp Projet : cjy7117/FT-MAGMA

// On input, LU and ipiv is LU factorization of A. On output, LU is overwritten.
// Works for any m, n.
// Uses init_matrix() to re-generate original A as needed.
// Returns error in factorization, |PA - LU| / (n |A|)
// This allocates 3 more matrices to store A, L, and U.
double get_LU_error(magma_int_t M, magma_int_t N,
                    double *LU, magma_int_t lda,
                    magma_int_t *ipiv)
{
    magma_int_t min_mn = min(M,N);
    magma_int_t ione   = 1;
    magma_int_t i, j;
    double alpha = MAGMA_D_ONE;
    double beta  = MAGMA_D_ZERO;
    double *A, *L, *U;
    double work[1], matnorm, residual;
    
    TESTING_MALLOC_CPU( A, double, lda*N    );
    TESTING_MALLOC_CPU( L, double, M*min_mn );
    TESTING_MALLOC_CPU( U, double, min_mn*N );
    memset( L, 0, M*min_mn*sizeof(double) );
    memset( U, 0, min_mn*N*sizeof(double) );

    // set to original A
    init_matrix( M, N, A, lda );
    lapackf77_dlaswp( &N, A, &lda, &ione, &min_mn, ipiv, &ione);
    
    // copy LU to L and U, and set diagonal to 1
    lapackf77_dlacpy( MagmaLowerStr, &M, &min_mn, LU, &lda, L, &M      );
    lapackf77_dlacpy( MagmaUpperStr, &min_mn, &N, LU, &lda, U, &min_mn );
    for(j=0; j<min_mn; j++)
        L[j+j*M] = MAGMA_D_MAKE( 1., 0. );
    
    matnorm = lapackf77_dlange("f", &M, &N, A, &lda, work);

    blasf77_dgemm("N", "N", &M, &N, &min_mn,
                  &alpha, L, &M, U, &min_mn, &beta, LU, &lda);

    for( j = 0; j < N; j++ ) {
        for( i = 0; i < M; i++ ) {
            LU[i+j*lda] = MAGMA_D_SUB( LU[i+j*lda], A[i+j*lda] );
        }
    }
    residual = lapackf77_dlange("f", &M, &N, LU, &lda, work);

    TESTING_FREE_CPU( A );
    TESTING_FREE_CPU( L );
    TESTING_FREE_CPU( U );

    return residual / (matnorm * N);
}

Exemple #2

Fichier : testing_dgetf2_gpu.cpp Projet : soulsheng/magma

double get_LU_error(magma_int_t M, magma_int_t N,
                    double *A,  magma_int_t lda,
                    double *LU, magma_int_t *IPIV)
{
    magma_int_t min_mn = min(M,N);
    magma_int_t ione   = 1;
    magma_int_t i, j;
    double alpha = MAGMA_D_ONE;
    double beta  = MAGMA_D_ZERO;
    double *L, *U;
    double work[1], matnorm, residual;
    
    TESTING_MALLOC( L, double, M*min_mn);
    TESTING_MALLOC( U, double, min_mn*N);
    memset( L, 0, M*min_mn*sizeof(double) );
    memset( U, 0, min_mn*N*sizeof(double) );

    lapackf77_dlaswp( &N, A, &lda, &ione, &min_mn, IPIV, &ione);
    lapackf77_dlacpy( MagmaLowerStr, &M, &min_mn, LU, &lda, L, &M      );
    lapackf77_dlacpy( MagmaUpperStr, &min_mn, &N, LU, &lda, U, &min_mn );

    for(j=0; j<min_mn; j++)
        L[j+j*M] = MAGMA_D_MAKE( 1., 0. );
    
    matnorm = lapackf77_dlange("f", &M, &N, A, &lda, work);

    blasf77_dgemm("N", "N", &M, &N, &min_mn,
                  &alpha, L, &M, U, &min_mn, &beta, LU, &lda);

    for( j = 0; j < N; j++ ) {
        for( i = 0; i < M; i++ ) {
            LU[i+j*lda] = MAGMA_D_SUB( LU[i+j*lda], A[i+j*lda] );
        }
    }
    residual = lapackf77_dlange("f", &M, &N, LU, &lda, work);

    TESTING_FREE(L);
    TESTING_FREE(U);

    return residual / (matnorm * N);
}