FLA_Chol_u_unb_var1.c File Reference

(r)

Functions
FLA_Error	FLA_Chol_u_unb_var1 (FLA_Obj A)

Function Documentation

FLA_Chol_u_unb_var1()

FLA_Error FLA_Chol_u_unb_var1

(

FLA_Obj

A

)

{
  FLA_Obj ATL,   ATR,      A00,  a01,     A02,
          ABL,   ABR,      a10t, alpha11, a12t,
                           A20,  a21,     A22;
 
  int r_val = FLA_SUCCESS;
 
  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 );
 
    /*------------------------------------------------------------*/
 
    // a01 = inv( tril( A00 )' ) * a01
    FLA_Trsv_external( FLA_UPPER_TRIANGULAR, FLA_CONJ_TRANSPOSE, FLA_NONUNIT_DIAG, A00, a01 );
 
    // alpha11 = alpha11 - a01' * a01
    FLA_Dotcs_external( FLA_CONJUGATE, FLA_MINUS_ONE, a01, a01, FLA_ONE, alpha11 );
 
    // alpha11 = sqrt( alpha11 )
    r_val = FLA_Sqrt( alpha11 );
 
    if ( r_val != FLA_SUCCESS )
      return ( FLA_Obj_length( A00 ) );
 
    /*------------------------------------------------------------*/
 
    FLA_Cont_with_3x3_to_2x2( &ATL, /**/ &ATR,       A00,  a01,     /**/ A02,
                                                     a10t, alpha11, /**/ a12t,
                            /* ************** */  /* ************************ */
                              &ABL, /**/ &ABR,       A20,  a21,     /**/ A22,
                              FLA_TL );
  }
 
  return r_val;
}

References FLA_Cont_with_3x3_to_2x2(), FLA_Dotcs_external(), FLA_MINUS_ONE, FLA_Obj_length(), FLA_ONE, FLA_Part_2x2(), FLA_Repart_2x2_to_3x3(), FLA_Sqrt(), FLA_Trsv_external(), and i.

Referenced by FLA_Chol_u().