FLA_Trinv_ln_unb_var4.c File Reference

(r)

Functions
FLA_Error	FLA_Trinv_ln_unb_var4 (FLA_Obj A)

---

Function Documentation

FLA_Error FLA_Trinv_ln_unb_var4

(

FLA_Obj

A

)

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_ln().

{
  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 );

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

    // a21 = -tril( A22 ) \ a21;
    FLA_Scal_external( FLA_MINUS_ONE, a21 );
    FLA_Trsv_external( FLA_LOWER_TRIANGULAR, FLA_NO_TRANSPOSE, FLA_NONUNIT_DIAG, A22, a21 );

    // A20 = -a21 * a10t + A20;
    FLA_Ger_external( FLA_MINUS_ONE, a21, a10t, A20 );

    // a10t' = tril( A00' ) * a10t';
    FLA_Trmv_external( FLA_LOWER_TRIANGULAR, FLA_TRANSPOSE, FLA_NONUNIT_DIAG, A00, a10t );

    // 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;
}