FLASH_LU_find_zero_on_diagonal.c File Reference

(r12600)

Functions
FLA_Error	FLASH_LU_find_zero_on_diagonal (FLA_Obj A)

---

Function Documentation

FLA_Error FLASH_LU_find_zero_on_diagonal

(

FLA_Obj

A

)

References FLA_Check_error_level(), FLA_Cont_with_3x3_to_2x2(), FLA_LU_find_zero_on_diagonal(), FLA_Obj_elemtype(), FLA_Obj_length(), FLA_Obj_min_dim(), FLA_Part_2x2(), FLA_Repart_2x2_to_3x3(), FLASH_LU_find_zero_on_diagonal_check(), and FLASH_Obj_scalar_length().

Referenced by FLASH_LU_nopiv(), and FLASH_LU_piv().

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

  FLA_Error e_val;

  if ( FLA_Check_error_level() >= FLA_MIN_ERROR_CHECKING )
    FLASH_LU_find_zero_on_diagonal_check( A );

  if ( FLA_Obj_elemtype( A ) == FLA_SCALAR )
    return FLA_LU_find_zero_on_diagonal( A );

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

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

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

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

    e_val = FLA_LU_find_zero_on_diagonal( *FLASH_OBJ_PTR_AT( alpha11 ) );

    if ( e_val != FLA_SUCCESS )
      return FLASH_Obj_scalar_length( A00 ) + e_val;

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

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

  return FLA_SUCCESS;
}