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FLA_Tevd_iteracc_n.h File Reference

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Functions

FLA_Error FLA_Tevd_iteracc_n_ops_var1 (int m_A, int n_G, int ijTL, float *buff_d, int inc_d, float *buff_e, int inc_e, int *n_iter_perf)
FLA_Error FLA_Tevd_iteracc_n_opd_var1 (int m_A, int n_G, int ijTL, double *buff_d, int inc_d, double *buff_e, int inc_e, int *n_iter_perf)

Function Documentation

FLA_Error FLA_Tevd_iteracc_n_opd_var1 ( int  m_A,
int  n_G,
int  ijTL,
double *  buff_d,
int  inc_d,
double *  buff_e,
int  inc_e,
int *  n_iter_perf 
)

References FLA_Hev_2x2_opd(), FLA_Tevd_eigval_n_opd_var1(), and FLA_Tevd_iteracc_n_opd_var1().

Referenced by FLA_Tevd_iteracc_n_opd_var1(), and FLA_Tevd_n_opz_var1().

{
    FLA_Error r_val;
    int       i, k;
    int       k_iter       = 0;
    int       n_deflations = 0;

    // Iterate from back to front until all that is left is a 2x2.
    for ( i = m_A - 1; i > 1; --i )
    {
        int       m_ATL  = i + 1;
        int       k_left = n_G - k_iter;

        /*------------------------------------------------------------*/

        // Search for an eigenvalue of ATL submatrix until
        //   (a) deflation occurs, or
        //   (b) we perform the maximum number of additional iterations
        //       that are allowed within the current sweep
        //       (ie: n_G - k_iter).
        r_val = FLA_Tevd_eigval_n_opd_var1( m_ATL,
                                            k_left,
                                            buff_d, inc_d,
                                            buff_e, inc_e,
                                            &k );

        // Update local counters according to the results of the eigenvalue
        // search.
        k_iter       += k;
        n_deflations += 1;

        // If the eigenvalue search did not result in any deflation, return.
        if ( r_val == FLA_FAILURE )
        {
#ifdef PRINTF
            printf( "FLA_Tevd_iteracc_n_opd_var1: failed to converge (m_A11 = %d) after %2d iters k_total=%d/%d\n", i, k, k_iter, n_G );
#endif
            *n_iter_perf = k_iter;
            return n_deflations;
        }

#ifdef PRINTF
        if ( r_val == i )
            printf( "FLA_Tevd_iteracc_n_opd_var1: found eig %22.15e in col %3d (n=%d) after %2d iters  k_total=%d/%d\n", buff_d[ r_val*inc_d ], ijTL+r_val, m_ATL, k, k_iter, n_G );
        else
            printf( "FLA_Tevd_iteracc_n_opd_var1: split occurred in col %3d (n=%d) after %2d iters  k_total=%d/%d\n", ijTL+r_val, m_ATL, k, k_iter, n_G );
#endif

        // If the most recent eigenvalue search put us at our limit
        // for accumulated Givens rotation sets, return.
        if ( k_iter == n_G )
        {
            *n_iter_perf = k_iter;
            return n_deflations;
        }


        // If r_val != i, then a split occurred somewhere within submatrix
        // ATL. Therefore, we must recurse with two subproblems.
        if ( r_val != i )
        {
            int       m_TLr = r_val + 1;
            int       m_BRr = m_ATL - m_TLr;
            int       ijTLr = 0;
            int       ijBRr = m_TLr;
            int       n_Gr  = n_G - k_iter;
            double*   dTL   = buff_d + (0    )*inc_d;
            double*   eTL   = buff_e + (0    )*inc_e;
            double*   dBR   = buff_d + (ijBRr)*inc_d;
            double*   eBR   = buff_e + (ijBRr)*inc_e;

            int       n_deflationsTL;
            int       n_deflationsBR;
            int       n_iter_perfTL;
            int       n_iter_perfBR;

#ifdef PRINTF
printf( "FLA_Tevd_iteracc_n_opd_var1: Internal deflation in col %d\n", ijTL+r_val );
printf( "FLA_Tevd_iteracc_n_opd_var1: alpha11         = %23.19e\n", buff_d[r_val*inc_d] );
printf( "FLA_Tevd_iteracc_n_opd_var1: alpha21 alpha22 = %23.19e %23.19e\n", buff_e[r_val*inc_e], buff_d[(r_val+1)*inc_d] );
#endif
#ifdef PRINTF
printf( "FLA_Tevd_iteracc_n_opd_var1: recursing: m_TLr m_BRr: %d %d\n", m_TLr, m_BRr );
printf( "FLA_Tevd_iteracc_n_opd_var1:            ijTLr ijBRr: %d %d\n", ijTLr, ijBRr );
printf( "FLA_Tevd_iteracc_n_opd_var1:            GB(0,0) i,j: %d %d\n", ijTL + m_TLr+1, k_iter );
#endif
            n_deflationsTL = FLA_Tevd_iteracc_n_opd_var1( m_TLr,
                                                          n_Gr,
                                                          ijTL + ijTLr,
                                                          dTL, inc_d,
                                                          eTL, inc_e,
                                                          &n_iter_perfTL );
            n_deflationsBR = FLA_Tevd_iteracc_n_opd_var1( m_BRr,
                                                          n_Gr,
                                                          ijTL + ijBRr,
                                                          dBR, inc_d,
                                                          eBR, inc_e,
                                                          &n_iter_perfBR );

            *n_iter_perf = k_iter + max( n_iter_perfTL, n_iter_perfBR );

#ifdef PRINTF
printf( "FLA_Tevd_iteracc_n_opd_var1: num deflations: %d = (prev:%d, TL:%d, BR:%d)\n", n_deflations + n_deflationsTL + n_deflationsBR, n_deflations, n_deflationsTL, n_deflationsBR );
printf( "FLA_Tevd_iteracc_n_opd_var1: num iterations: %d = (prev:%d, TL:%d, BR:%d)\n", *n_iter_perf, k_iter, n_iter_perfTL, n_iter_perfBR );
#endif
            return n_deflations + n_deflationsTL + n_deflationsBR;
        }

        /*------------------------------------------------------------*/
    }

    // Skip 1x1 matrices (and submatrices) entirely.
    if ( m_A > 1 )
    {
        double*   alpha11 = buff_d + (0  )*inc_d;
        double*   alpha21 = buff_e + (0  )*inc_e;
        double*   alpha22 = buff_d + (1  )*inc_d;
        double    lambda1;
        double    lambda2;

        // Find the eigenvalue decomposition of the remaining (or only) 2x2
        // submatrix.
        FLA_Hev_2x2_opd( alpha11,
                         alpha21,
                         alpha22,
                         &lambda1,
                         &lambda2 );

        // Store the eigenvalues.
        *alpha11 = lambda1;
        *alpha22 = lambda2;

        // Zero out the remaining subdiagonal element.
        *alpha21 = 0.0;

        // Update the local counters.
        k_iter       += 1;
        n_deflations += 1;

#ifdef PRINTF
printf( "FLA_Tevd_iteracc_n_opd_var1: Hevv  eig %22.15e in col %3d (n=%d) after %2d iters  k_total=%d/%d\n", buff_d[ 1*inc_d ], ijTL+1, 2, 1, k_iter, n_G );
printf( "FLA_Tevd_iteracc_n_opd_var1: Hevv  eig %22.15e in col %3d (n=%d) after %2d iters  k_total=%d/%d\n", buff_d[ 0*inc_d ], ijTL+0, 2, 0, k_iter, n_G );
#endif
    }


    *n_iter_perf = k_iter;
    return n_deflations;
}
FLA_Error FLA_Tevd_iteracc_n_ops_var1 ( int  m_A,
int  n_G,
int  ijTL,
float *  buff_d,
int  inc_d,
float *  buff_e,
int  inc_e,
int *  n_iter_perf 
)
{
    return FLA_SUCCESS;
}