FLA_Lyap_n_blk_var4.c File Reference

(r)

Functions
FLA_Error	FLA_Lyap_n_blk_var4 (FLA_Obj isgn, FLA_Obj A, FLA_Obj C, FLA_Obj scale, fla_lyap_t *cntl)

Function Documentation

FLA_Lyap_n_blk_var4()

FLA_Error FLA_Lyap_n_blk_var4	(	FLA_Obj	isgn,
		FLA_Obj	A,
		FLA_Obj	C,
		FLA_Obj	scale,
		fla_lyap_t *	cntl
	)

{
  FLA_Obj ATL,   ATR,      A00, A01, A02, 
          ABL,   ABR,      A10, A11, A12,
                           A20, A21, A22;
  FLA_Obj CTL,   CTR,      C00, C01, C02, 
          CBL,   CBR,      C10, C11, C12,
                           C20, C21, C22;
  dim_t   b;
 
  // C = isgn * C;
  FLA_Scal_internal( isgn, C,
                     FLA_Cntl_sub_scal( cntl ) );
 
  FLA_Part_2x2( A,    &ATL, &ATR,
                      &ABL, &ABR,     0, 0, FLA_BR );
 
  FLA_Part_2x2( C,    &CTL, &CTR,
                      &CBL, &CBR,     0, 0, FLA_BR );
 
  while ( FLA_Obj_length( CTL ) > 0 ){
 
    b = FLA_Determine_blocksize( CTL, FLA_TL, FLA_Cntl_blocksize( cntl ) );
 
    FLA_Repart_2x2_to_3x3( ATL, /**/ ATR,       &A00, &A01, /**/ &A02,
                                                &A10, &A11, /**/ &A12,
                        /* ************* */   /* ******************** */
                           ABL, /**/ ABR,       &A20, &A21, /**/ &A22,
                           b, b, FLA_TL );
 
    FLA_Repart_2x2_to_3x3( CTL, /**/ CTR,       &C00, &C01, /**/ &C02,
                                                &C10, &C11, /**/ &C12,
                        /* ************* */   /* ******************** */
                           CBL, /**/ CBR,       &C20, &C21, /**/ &C22,
                           b, b, FLA_TL );
 
    /*------------------------------------------------------------*/
 
    // C11 = lyap_n( A11, C11 );
    FLA_Lyap_internal( FLA_NO_TRANSPOSE, FLA_ONE, A11, C11, scale,
                       FLA_Cntl_sub_lyap( cntl ) );
 
    // C01 = C01 - A01 * C11;
    // C01 = sylv( A00, A11', C01 );
    FLA_Hemm_internal( FLA_RIGHT, FLA_UPPER_TRIANGULAR,
                       FLA_MINUS_ONE, C11, A01, FLA_ONE, C01,
                       FLA_Cntl_sub_hemm( cntl ) );
    FLA_Sylv_internal( FLA_NO_TRANSPOSE, FLA_CONJ_TRANSPOSE,
                       FLA_ONE, A00, A11, C01, scale,
                       FLA_Cntl_sub_sylv( cntl ) );
 
    // C00 = C00 - A01 * C01' - C01 * A01';
    FLA_Her2k_internal( FLA_UPPER_TRIANGULAR, FLA_NO_TRANSPOSE,
                        FLA_MINUS_ONE, A01, C01, FLA_ONE, C00,
                        FLA_Cntl_sub_her2k( cntl ) );
 
    /*------------------------------------------------------------*/
 
    FLA_Cont_with_3x3_to_2x2( &ATL, /**/ &ATR,       A00, /**/ A01, A02,
                            /* ************** */  /* ****************** */
                                                     A10, /**/ A11, A12,
                              &ABL, /**/ &ABR,       A20, /**/ A21, A22,
                              FLA_BR );
 
    FLA_Cont_with_3x3_to_2x2( &CTL, /**/ &CTR,       C00, /**/ C01, C02,
                            /* ************** */  /* ****************** */
                                                     C10, /**/ C11, C12,
                              &CBL, /**/ &CBR,       C20, /**/ C21, C22,
                              FLA_BR );
  }
 
  return FLA_SUCCESS;
}

References FLA_Cont_with_3x3_to_2x2(), FLA_Determine_blocksize(), FLA_Hemm_internal(), FLA_Her2k_internal(), FLA_Lyap_internal(), FLA_MINUS_ONE, FLA_Obj_length(), FLA_ONE, FLA_Part_2x2(), FLA_Repart_2x2_to_3x3(), FLA_Scal_internal(), FLA_Sylv_internal(), and i.

Referenced by FLA_Lyap_n().