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Functions
FLA_LQ_UT_unb_var1.c File Reference

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Functions

FLA_Error FLA_LQ_UT_unb_var1 (FLA_Obj A, FLA_Obj t)
 

Function Documentation

◆ FLA_LQ_UT_unb_var1()

FLA_Error FLA_LQ_UT_unb_var1 ( FLA_Obj  A,
FLA_Obj  t 
)

References FLA_Apply_H2_UT(), FLA_Cont_with_1x3_to_1x2(), FLA_Cont_with_3x3_to_2x2(), FLA_Househ2_UT(), FLA_Obj_min_dim(), FLA_Part_1x2(), FLA_Part_2x2(), FLA_Repart_1x2_to_1x3(), and FLA_Repart_2x2_to_3x3().

Referenced by FLA_LQ_UT_internal().

14 {
15  FLA_Obj ATL, ATR, A00, a01, A02,
16  ABL, ABR, a10t, alpha11, a12t,
17  A20, a21, A22;
18 
19  FLA_Obj tLt, tRt, t0t, tau1, t2t;
20 
21  FLA_Part_2x2( A, &ATL, &ATR,
22  &ABL, &ABR, 0, 0, FLA_TL );
23 
24  FLA_Part_1x2( t, &tLt, &tRt, 0, FLA_LEFT );
25 
26  while ( FLA_Obj_min_dim( ABR ) > 0 ){
27 
28  FLA_Repart_2x2_to_3x3( ATL, /**/ ATR, &A00, /**/ &a01, &A02,
29  /* ************* */ /* ************************** */
30  &a10t, /**/ &alpha11, &a12t,
31  ABL, /**/ ABR, &A20, /**/ &a21, &A22,
32  1, 1, FLA_BR );
33 
34  FLA_Repart_1x2_to_1x3( tLt, /**/ tRt, &t0t, /**/ &tau1, &t2t,
35  1, FLA_RIGHT );
36 
37  /*------------------------------------------------------------*/
38 
39  // Compute tau11 and u12t from alpha11 and a12t such that tau11 and u12t
40  // determine a Householder transform H such that applying H from the
41  // right to the row vector consisting of alpha11 and a12t annihilates
42  // the entries in a12t (and updates alpha11).
43  FLA_Househ2_UT( FLA_RIGHT, alpha11, a12t,
44  tau1 );
45 
46  // ( a21 A22 ) = ( a21 A22 ) H
47  //
48  // where H is formed from tau11 and u12t.
49  FLA_Apply_H2_UT( FLA_RIGHT, tau1, a12t, a21, A22 );
50 
51  /*------------------------------------------------------------*/
52 
53  FLA_Cont_with_3x3_to_2x2( &ATL, /**/ &ATR, A00, a01, /**/ A02,
54  a10t, alpha11, /**/ a12t,
55  /* ************** */ /* ************************ */
56  &ABL, /**/ &ABR, A20, a21, /**/ A22,
57  FLA_TL );
58 
59  FLA_Cont_with_1x3_to_1x2( &tLt, /**/ &tRt, t0t, tau1, /**/ t2t,
60  FLA_LEFT );
61  }
62 
63  return FLA_SUCCESS;
64 }
FLA_Error FLA_Househ2_UT(FLA_Side side, FLA_Obj chi_1, FLA_Obj x2, FLA_Obj tau)
Definition: FLA_Househ2_UT.c:16
FLA_Error FLA_Repart_1x2_to_1x3(FLA_Obj AL, FLA_Obj AR, FLA_Obj *A0, FLA_Obj *A1, FLA_Obj *A2, dim_t nb, FLA_Side side)
Definition: FLA_View.c:267
FLA_Error FLA_Repart_2x2_to_3x3(FLA_Obj ATL, FLA_Obj ATR, FLA_Obj *A00, FLA_Obj *A01, FLA_Obj *A02, FLA_Obj *A10, FLA_Obj *A11, FLA_Obj *A12, FLA_Obj ABL, FLA_Obj ABR, FLA_Obj *A20, FLA_Obj *A21, FLA_Obj *A22, dim_t mb, dim_t nb, FLA_Quadrant quadrant)
Definition: FLA_View.c:142
FLA_Error FLA_Apply_H2_UT(FLA_Side side, FLA_Obj tau, FLA_Obj u2, FLA_Obj a1, FLA_Obj A2)
Definition: FLA_Apply_H2_UT.c:13
FLA_Error FLA_Part_2x2(FLA_Obj A, FLA_Obj *A11, FLA_Obj *A12, FLA_Obj *A21, FLA_Obj *A22, dim_t mb, dim_t nb, FLA_Quadrant quadrant)
Definition: FLA_View.c:17
Definition: FLA_type_defs.h:158
FLA_Error FLA_Cont_with_1x3_to_1x2(FLA_Obj *AL, FLA_Obj *AR, FLA_Obj A0, FLA_Obj A1, FLA_Obj A2, FLA_Side side)
Definition: FLA_View.c:475
FLA_Error FLA_Cont_with_3x3_to_2x2(FLA_Obj *ATL, FLA_Obj *ATR, FLA_Obj A00, FLA_Obj A01, FLA_Obj A02, FLA_Obj A10, FLA_Obj A11, FLA_Obj A12, FLA_Obj *ABL, FLA_Obj *ABR, FLA_Obj A20, FLA_Obj A21, FLA_Obj A22, FLA_Quadrant quadrant)
Definition: FLA_View.c:304
FLA_Error FLA_Part_1x2(FLA_Obj A, FLA_Obj *A1, FLA_Obj *A2, dim_t nb, FLA_Side side)
Definition: FLA_View.c:110
dim_t FLA_Obj_min_dim(FLA_Obj obj)
Definition: FLA_Query.c:153