slasda.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 414 行 · 第 1/2 页

<span class="comment">*</span><span class="comment">
</span>      IF( ( ICOMPQ.LT.0 ) .OR. ( ICOMPQ.GT.1 ) ) THEN
         INFO = -1
      ELSE IF( SMLSIZ.LT.3 ) THEN
         INFO = -2
      ELSE IF( N.LT.0 ) THEN
         INFO = -3
      ELSE IF( ( SQRE.LT.0 ) .OR. ( SQRE.GT.1 ) ) THEN
         INFO = -4
      ELSE IF( LDU.LT.( N+SQRE ) ) THEN
         INFO = -8
      ELSE IF( LDGCOL.LT.N ) THEN
         INFO = -17
      END IF
      IF( INFO.NE.0 ) THEN
         CALL <a name="XERBLA.204"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>( <span class="string">'<a name="SLASDA.204"></a><a href="slasda.f.html#SLASDA.1">SLASDA</a>'</span>, -INFO )
         RETURN
      END IF
<span class="comment">*</span><span class="comment">
</span>      M = N + SQRE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     If the input matrix is too small, call <a name="SLASDQ.210"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a> to find the SVD.
</span><span class="comment">*</span><span class="comment">
</span>      IF( N.LE.SMLSIZ ) THEN
         IF( ICOMPQ.EQ.0 ) THEN
            CALL <a name="SLASDQ.214"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>( <span class="string">'U'</span>, SQRE, N, 0, 0, 0, D, E, VT, LDU, U, LDU,
     $                   U, LDU, WORK, INFO )
         ELSE
            CALL <a name="SLASDQ.217"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>( <span class="string">'U'</span>, SQRE, N, M, N, 0, D, E, VT, LDU, U, LDU,
     $                   U, LDU, WORK, INFO )
         END IF
         RETURN
      END IF
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Book-keeping and  set up the computation tree.
</span><span class="comment">*</span><span class="comment">
</span>      INODE = 1
      NDIML = INODE + N
      NDIMR = NDIML + N
      IDXQ = NDIMR + N
      IWK = IDXQ + N
<span class="comment">*</span><span class="comment">
</span>      NCC = 0
      NRU = 0
<span class="comment">*</span><span class="comment">
</span>      SMLSZP = SMLSIZ + 1
      VF = 1
      VL = VF + M
      NWORK1 = VL + M
      NWORK2 = NWORK1 + SMLSZP*SMLSZP
<span class="comment">*</span><span class="comment">
</span>      CALL <a name="SLASDT.240"></a><a href="slasdt.f.html#SLASDT.1">SLASDT</a>( N, NLVL, ND, IWORK( INODE ), IWORK( NDIML ),
     $             IWORK( NDIMR ), SMLSIZ )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     for the nodes on bottom level of the tree, solve
</span><span class="comment">*</span><span class="comment">     their subproblems by <a name="SLASDQ.244"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>.
</span><span class="comment">*</span><span class="comment">
</span>      NDB1 = ( ND+1 ) / 2
      DO 30 I = NDB1, ND
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        IC : center row of each node
</span><span class="comment">*</span><span class="comment">        NL : number of rows of left  subproblem
</span><span class="comment">*</span><span class="comment">        NR : number of rows of right subproblem
</span><span class="comment">*</span><span class="comment">        NLF: starting row of the left   subproblem
</span><span class="comment">*</span><span class="comment">        NRF: starting row of the right  subproblem
</span><span class="comment">*</span><span class="comment">
</span>         I1 = I - 1
         IC = IWORK( INODE+I1 )
         NL = IWORK( NDIML+I1 )
         NLP1 = NL + 1
         NR = IWORK( NDIMR+I1 )
         NLF = IC - NL
         NRF = IC + 1
         IDXQI = IDXQ + NLF - 2
         VFI = VF + NLF - 1
         VLI = VL + NLF - 1
         SQREI = 1
         IF( ICOMPQ.EQ.0 ) THEN
            CALL <a name="SLASET.267"></a><a href="slaset.f.html#SLASET.1">SLASET</a>( <span class="string">'A'</span>, NLP1, NLP1, ZERO, ONE, WORK( NWORK1 ),
     $                   SMLSZP )
            CALL <a name="SLASDQ.269"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>( <span class="string">'U'</span>, SQREI, NL, NLP1, NRU, NCC, D( NLF ),
     $                   E( NLF ), WORK( NWORK1 ), SMLSZP,
     $                   WORK( NWORK2 ), NL, WORK( NWORK2 ), NL,
     $                   WORK( NWORK2 ), INFO )
            ITEMP = NWORK1 + NL*SMLSZP
            CALL SCOPY( NLP1, WORK( NWORK1 ), 1, WORK( VFI ), 1 )
            CALL SCOPY( NLP1, WORK( ITEMP ), 1, WORK( VLI ), 1 )
         ELSE
            CALL <a name="SLASET.277"></a><a href="slaset.f.html#SLASET.1">SLASET</a>( <span class="string">'A'</span>, NL, NL, ZERO, ONE, U( NLF, 1 ), LDU )
            CALL <a name="SLASET.278"></a><a href="slaset.f.html#SLASET.1">SLASET</a>( <span class="string">'A'</span>, NLP1, NLP1, ZERO, ONE, VT( NLF, 1 ), LDU )
            CALL <a name="SLASDQ.279"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>( <span class="string">'U'</span>, SQREI, NL, NLP1, NL, NCC, D( NLF ),
     $                   E( NLF ), VT( NLF, 1 ), LDU, U( NLF, 1 ), LDU,
     $                   U( NLF, 1 ), LDU, WORK( NWORK1 ), INFO )
            CALL SCOPY( NLP1, VT( NLF, 1 ), 1, WORK( VFI ), 1 )
            CALL SCOPY( NLP1, VT( NLF, NLP1 ), 1, WORK( VLI ), 1 )
         END IF
         IF( INFO.NE.0 ) THEN
            RETURN
         END IF
         DO 10 J = 1, NL
            IWORK( IDXQI+J ) = J
   10    CONTINUE
         IF( ( I.EQ.ND ) .AND. ( SQRE.EQ.0 ) ) THEN
            SQREI = 0
         ELSE
            SQREI = 1
         END IF
         IDXQI = IDXQI + NLP1
         VFI = VFI + NLP1
         VLI = VLI + NLP1
         NRP1 = NR + SQREI
         IF( ICOMPQ.EQ.0 ) THEN
            CALL <a name="SLASET.301"></a><a href="slaset.f.html#SLASET.1">SLASET</a>( <span class="string">'A'</span>, NRP1, NRP1, ZERO, ONE, WORK( NWORK1 ),
     $                   SMLSZP )
            CALL <a name="SLASDQ.303"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>( <span class="string">'U'</span>, SQREI, NR, NRP1, NRU, NCC, D( NRF ),
     $                   E( NRF ), WORK( NWORK1 ), SMLSZP,
     $                   WORK( NWORK2 ), NR, WORK( NWORK2 ), NR,
     $                   WORK( NWORK2 ), INFO )
            ITEMP = NWORK1 + ( NRP1-1 )*SMLSZP
            CALL SCOPY( NRP1, WORK( NWORK1 ), 1, WORK( VFI ), 1 )
            CALL SCOPY( NRP1, WORK( ITEMP ), 1, WORK( VLI ), 1 )
         ELSE
            CALL <a name="SLASET.311"></a><a href="slaset.f.html#SLASET.1">SLASET</a>( <span class="string">'A'</span>, NR, NR, ZERO, ONE, U( NRF, 1 ), LDU )
            CALL <a name="SLASET.312"></a><a href="slaset.f.html#SLASET.1">SLASET</a>( <span class="string">'A'</span>, NRP1, NRP1, ZERO, ONE, VT( NRF, 1 ), LDU )
            CALL <a name="SLASDQ.313"></a><a href="slasdq.f.html#SLASDQ.1">SLASDQ</a>( <span class="string">'U'</span>, SQREI, NR, NRP1, NR, NCC, D( NRF ),
     $                   E( NRF ), VT( NRF, 1 ), LDU, U( NRF, 1 ), LDU,
     $                   U( NRF, 1 ), LDU, WORK( NWORK1 ), INFO )
            CALL SCOPY( NRP1, VT( NRF, 1 ), 1, WORK( VFI ), 1 )
            CALL SCOPY( NRP1, VT( NRF, NRP1 ), 1, WORK( VLI ), 1 )
         END IF
         IF( INFO.NE.0 ) THEN
            RETURN
         END IF
         DO 20 J = 1, NR
            IWORK( IDXQI+J ) = J
   20    CONTINUE
   30 CONTINUE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Now conquer each subproblem bottom-up.
</span><span class="comment">*</span><span class="comment">
</span>      J = 2**NLVL
      DO 50 LVL = NLVL, 1, -1
         LVL2 = LVL*2 - 1
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        Find the first node LF and last node LL on
</span><span class="comment">*</span><span class="comment">        the current level LVL.
</span><span class="comment">*</span><span class="comment">
</span>         IF( LVL.EQ.1 ) THEN
            LF = 1
            LL = 1
         ELSE
            LF = 2**( LVL-1 )
            LL = 2*LF - 1
         END IF
         DO 40 I = LF, LL
            IM1 = I - 1
            IC = IWORK( INODE+IM1 )
            NL = IWORK( NDIML+IM1 )
            NR = IWORK( NDIMR+IM1 )
            NLF = IC - NL
            NRF = IC + 1
            IF( I.EQ.LL ) THEN
               SQREI = SQRE
            ELSE
               SQREI = 1
            END IF
            VFI = VF + NLF - 1
            VLI = VL + NLF - 1
            IDXQI = IDXQ + NLF - 1
            ALPHA = D( IC )
            BETA = E( IC )
            IF( ICOMPQ.EQ.0 ) THEN
               CALL <a name="SLASD6.361"></a><a href="slasd6.f.html#SLASD6.1">SLASD6</a>( ICOMPQ, NL, NR, SQREI, D( NLF ),
     $                      WORK( VFI ), WORK( VLI ), ALPHA, BETA,
     $                      IWORK( IDXQI ), PERM, GIVPTR( 1 ), GIVCOL,
     $                      LDGCOL, GIVNUM, LDU, POLES, DIFL, DIFR, Z,
     $                      K( 1 ), C( 1 ), S( 1 ), WORK( NWORK1 ),
     $                      IWORK( IWK ), INFO )
            ELSE
               J = J - 1
               CALL <a name="SLASD6.369"></a><a href="slasd6.f.html#SLASD6.1">SLASD6</a>( ICOMPQ, NL, NR, SQREI, D( NLF ),
     $                      WORK( VFI ), WORK( VLI ), ALPHA, BETA,
     $                      IWORK( IDXQI ), PERM( NLF, LVL ),
     $                      GIVPTR( J ), GIVCOL( NLF, LVL2 ), LDGCOL,
     $                      GIVNUM( NLF, LVL2 ), LDU,
     $                      POLES( NLF, LVL2 ), DIFL( NLF, LVL ),
     $                      DIFR( NLF, LVL2 ), Z( NLF, LVL ), K( J ),
     $                      C( J ), S( J ), WORK( NWORK1 ),
     $                      IWORK( IWK ), INFO )
            END IF
            IF( INFO.NE.0 ) THEN
               RETURN
            END IF
   40    CONTINUE
   50 CONTINUE
<span class="comment">*</span><span class="comment">
</span>      RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     End of <a name="SLASDA.387"></a><a href="slasda.f.html#SLASDA.1">SLASDA</a>
</span><span class="comment">*</span><span class="comment">
</span>      END

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