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Functions
FLA_Trinv_un_unb_var4.c File Reference

(r)

Functions

FLA_Error FLA_Trinv_un_unb_var4 (FLA_Obj A)

Function Documentation

References FLA_Cont_with_3x3_to_2x2(), FLA_Ger_external(), FLA_Invert(), FLA_MINUS_ONE, FLA_Obj_length(), FLA_Part_2x2(), FLA_Repart_2x2_to_3x3(), FLA_Scal_external(), FLA_Trmv_external(), and FLA_Trsv_external().

Referenced by FLA_Trinv_un().

{
  FLA_Obj ATL,   ATR,      A00,  a01,     A02, 
          ABL,   ABR,      a10t, alpha11, a12t,
                           A20,  a21,     A22;

  FLA_Part_2x2( A,    &ATL, &ATR,
                      &ABL, &ABR,     0, 0, FLA_TL );

  while ( FLA_Obj_length( ATL ) < FLA_Obj_length( A ) ){

    FLA_Repart_2x2_to_3x3( ATL, /**/ ATR,       &A00,  /**/ &a01,     &A02,
                        /* ************* */   /* ************************** */
                                                &a10t, /**/ &alpha11, &a12t,
                           ABL, /**/ ABR,       &A20,  /**/ &a21,     &A22,
                           1, 1, FLA_BR );

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

    // a12t = a12t / triu( A22' );
    FLA_Scal_external( FLA_MINUS_ONE, a12t );
    FLA_Trsv_external( FLA_UPPER_TRIANGULAR, FLA_TRANSPOSE, FLA_NONUNIT_DIAG, A22, a12t );

    // A02 = -a01 * a12t + A02;
    FLA_Ger_external( FLA_MINUS_ONE, a01, a12t, A02 );

    // a01 = triu( A00 ) * a01;
    FLA_Trmv_external( FLA_UPPER_TRIANGULAR, FLA_NO_TRANSPOSE, FLA_NONUNIT_DIAG, A00, a01 );

    // alpha11 = 1.0 / alpha11;
    FLA_Invert( FLA_NO_CONJUGATE, alpha11 );

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

    FLA_Cont_with_3x3_to_2x2( &ATL, /**/ &ATR,       A00,  a01,     /**/ A02,
                                                     a10t, alpha11, /**/ a12t,
                            /* ************** */  /* ************************ */
                              &ABL, /**/ &ABR,       A20,  a21,     /**/ A22,
                              FLA_TL );

  }

  return FLA_SUCCESS;
}