cggesx.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 603 行 · 第 1/4 页

</span><span class="comment">*</span><span class="comment">  VSL     (output) COMPLEX array, dimension (LDVSL,N)
</span><span class="comment">*</span><span class="comment">          If JOBVSL = 'V', VSL will contain the left Schur vectors.
</span><span class="comment">*</span><span class="comment">          Not referenced if JOBVSL = 'N'.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  LDVSL   (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The leading dimension of the matrix VSL. LDVSL &gt;=1, and
</span><span class="comment">*</span><span class="comment">          if JOBVSL = 'V', LDVSL &gt;= N.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  VSR     (output) COMPLEX array, dimension (LDVSR,N)
</span><span class="comment">*</span><span class="comment">          If JOBVSR = 'V', VSR will contain the right Schur vectors.
</span><span class="comment">*</span><span class="comment">          Not referenced if JOBVSR = 'N'.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  LDVSR   (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The leading dimension of the matrix VSR. LDVSR &gt;= 1, and
</span><span class="comment">*</span><span class="comment">          if JOBVSR = 'V', LDVSR &gt;= N.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  RCONDE  (output) REAL array, dimension ( 2 )
</span><span class="comment">*</span><span class="comment">          If SENSE = 'E' or 'B', RCONDE(1) and RCONDE(2) contain the
</span><span class="comment">*</span><span class="comment">          reciprocal condition numbers for the average of the selected
</span><span class="comment">*</span><span class="comment">          eigenvalues.
</span><span class="comment">*</span><span class="comment">          Not referenced if SENSE = 'N' or 'V'.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  RCONDV  (output) REAL array, dimension ( 2 )
</span><span class="comment">*</span><span class="comment">          If SENSE = 'V' or 'B', RCONDV(1) and RCONDV(2) contain the
</span><span class="comment">*</span><span class="comment">          reciprocal condition number for the selected deflating
</span><span class="comment">*</span><span class="comment">          subspaces.
</span><span class="comment">*</span><span class="comment">          Not referenced if SENSE = 'N' or 'E'.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  WORK    (workspace/output) COMPLEX array, dimension (MAX(1,LWORK))
</span><span class="comment">*</span><span class="comment">          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  LWORK   (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The dimension of the array WORK.
</span><span class="comment">*</span><span class="comment">          If N = 0, LWORK &gt;= 1, else if SENSE = 'E', 'V', or 'B',
</span><span class="comment">*</span><span class="comment">          LWORK &gt;= MAX(1,2*N,2*SDIM*(N-SDIM)), else
</span><span class="comment">*</span><span class="comment">          LWORK &gt;= MAX(1,2*N).  Note that 2*SDIM*(N-SDIM) &lt;= N*N/2.
</span><span class="comment">*</span><span class="comment">          Note also that an error is only returned if
</span><span class="comment">*</span><span class="comment">          LWORK &lt; MAX(1,2*N), but if SENSE = 'E' or 'V' or 'B' this may
</span><span class="comment">*</span><span class="comment">          not be large enough.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">          If LWORK = -1, then a workspace query is assumed; the routine
</span><span class="comment">*</span><span class="comment">          only calculates the bound on the optimal size of the WORK
</span><span class="comment">*</span><span class="comment">          array and the minimum size of the IWORK array, returns these
</span><span class="comment">*</span><span class="comment">          values as the first entries of the WORK and IWORK arrays, and
</span><span class="comment">*</span><span class="comment">          no error message related to LWORK or LIWORK is issued by
</span><span class="comment">*</span><span class="comment">          <a name="XERBLA.178"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  RWORK   (workspace) REAL array, dimension ( 8*N )
</span><span class="comment">*</span><span class="comment">          Real workspace.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK))
</span><span class="comment">*</span><span class="comment">          On exit, if INFO = 0, IWORK(1) returns the minimum LIWORK.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  LIWORK  (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The dimension of the array WORK.
</span><span class="comment">*</span><span class="comment">          If SENSE = 'N' or N = 0, LIWORK &gt;= 1, otherwise
</span><span class="comment">*</span><span class="comment">          LIWORK &gt;= N+2.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">          If LIWORK = -1, then a workspace query is assumed; the
</span><span class="comment">*</span><span class="comment">          routine only calculates the bound on the optimal size of the
</span><span class="comment">*</span><span class="comment">          WORK array and the minimum size of the IWORK array, returns
</span><span class="comment">*</span><span class="comment">          these values as the first entries of the WORK and IWORK
</span><span class="comment">*</span><span class="comment">          arrays, and no error message related to LWORK or LIWORK is
</span><span class="comment">*</span><span class="comment">          issued by <a name="XERBLA.196"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  BWORK   (workspace) LOGICAL array, dimension (N)
</span><span class="comment">*</span><span class="comment">          Not referenced if SORT = 'N'.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  INFO    (output) INTEGER
</span><span class="comment">*</span><span class="comment">          = 0:  successful exit
</span><span class="comment">*</span><span class="comment">          &lt; 0:  if INFO = -i, the i-th argument had an illegal value.
</span><span class="comment">*</span><span class="comment">          = 1,...,N:
</span><span class="comment">*</span><span class="comment">                The QZ iteration failed.  (A,B) are not in Schur
</span><span class="comment">*</span><span class="comment">                form, but ALPHA(j) and BETA(j) should be correct for
</span><span class="comment">*</span><span class="comment">                j=INFO+1,...,N.
</span><span class="comment">*</span><span class="comment">          &gt; N:  =N+1: other than QZ iteration failed in <a name="CHGEQZ.208"></a><a href="chgeqz.f.html#CHGEQZ.1">CHGEQZ</a>
</span><span class="comment">*</span><span class="comment">                =N+2: after reordering, roundoff changed values of
</span><span class="comment">*</span><span class="comment">                      some complex eigenvalues so that leading
</span><span class="comment">*</span><span class="comment">                      eigenvalues in the Generalized Schur form no
</span><span class="comment">*</span><span class="comment">                      longer satisfy SELCTG=.TRUE.  This could also
</span><span class="comment">*</span><span class="comment">                      be caused due to scaling.
</span><span class="comment">*</span><span class="comment">                =N+3: reordering failed in <a name="CTGSEN.214"></a><a href="ctgsen.f.html#CTGSEN.1">CTGSEN</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  =====================================================================
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     .. Parameters ..
</span>      REAL               ZERO, ONE
      PARAMETER          ( ZERO = 0.0E+0, ONE = 1.0E+0 )
      COMPLEX            CZERO, CONE
      PARAMETER          ( CZERO = ( 0.0E+0, 0.0E+0 ),
     $                   CONE = ( 1.0E+0, 0.0E+0 ) )
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Local Scalars ..
</span>      LOGICAL            CURSL, ILASCL, ILBSCL, ILVSL, ILVSR, LASTSL,
     $                   LQUERY, WANTSB, WANTSE, WANTSN, WANTST, WANTSV
      INTEGER            I, ICOLS, IERR, IHI, IJOB, IJOBVL, IJOBVR,
     $                   ILEFT, ILO, IRIGHT, IROWS, IRWRK, ITAU, IWRK,
     $                   LIWMIN, LWRK, MAXWRK, MINWRK
      REAL               ANRM, ANRMTO, BIGNUM, BNRM, BNRMTO, EPS, PL,
     $                   PR, SMLNUM
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Local Arrays ..
</span>      REAL               DIF( 2 )
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. External Subroutines ..
</span>      EXTERNAL           <a name="CGEQRF.238"></a><a href="cgeqrf.f.html#CGEQRF.1">CGEQRF</a>, <a name="CGGBAK.238"></a><a href="cggbak.f.html#CGGBAK.1">CGGBAK</a>, <a name="CGGBAL.238"></a><a href="cggbal.f.html#CGGBAL.1">CGGBAL</a>, <a name="CGGHRD.238"></a><a href="cgghrd.f.html#CGGHRD.1">CGGHRD</a>, <a name="CHGEQZ.238"></a><a href="chgeqz.f.html#CHGEQZ.1">CHGEQZ</a>, <a name="CLACPY.238"></a><a href="clacpy.f.html#CLACPY.1">CLACPY</a>,
     $                   <a name="CLASCL.239"></a><a href="clascl.f.html#CLASCL.1">CLASCL</a>, <a name="CLASET.239"></a><a href="claset.f.html#CLASET.1">CLASET</a>, <a name="CTGSEN.239"></a><a href="ctgsen.f.html#CTGSEN.1">CTGSEN</a>, <a name="CUNGQR.239"></a><a href="cungqr.f.html#CUNGQR.1">CUNGQR</a>, <a name="CUNMQR.239"></a><a href="cunmqr.f.html#CUNMQR.1">CUNMQR</a>, <a name="SLABAD.239"></a><a href="slabad.f.html#SLABAD.1">SLABAD</a>,
     $                   <a name="XERBLA.240"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. External Functions ..
</span>      LOGICAL            <a name="LSAME.243"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
      INTEGER            <a name="ILAENV.244"></a><a href="hfy-index.html#ILAENV">ILAENV</a>
      REAL               <a name="CLANGE.245"></a><a href="clange.f.html#CLANGE.1">CLANGE</a>, <a name="SLAMCH.245"></a><a href="slamch.f.html#SLAMCH.1">SLAMCH</a>
      EXTERNAL           <a name="LSAME.246"></a><a href="lsame.f.html#LSAME.1">LSAME</a>, <a name="ILAENV.246"></a><a href="hfy-index.html#ILAENV">ILAENV</a>, <a name="CLANGE.246"></a><a href="clange.f.html#CLANGE.1">CLANGE</a>, <a name="SLAMCH.246"></a><a href="slamch.f.html#SLAMCH.1">SLAMCH</a>
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Intrinsic Functions ..
</span>      INTRINSIC          MAX, SQRT
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Executable Statements ..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Decode the input arguments
</span><span class="comment">*</span><span class="comment">
</span>      IF( <a name="LSAME.255"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( JOBVSL, <span class="string">'N'</span> ) ) THEN
         IJOBVL = 1
         ILVSL = .FALSE.
      ELSE IF( <a name="LSAME.258"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( JOBVSL, <span class="string">'V'</span> ) ) THEN
         IJOBVL = 2
         ILVSL = .TRUE.
      ELSE
         IJOBVL = -1
         ILVSL = .FALSE.
      END IF
<span class="comment">*</span><span class="comment">
</span>      IF( <a name="LSAME.266"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( JOBVSR, <span class="string">'N'</span> ) ) THEN
         IJOBVR = 1
         ILVSR = .FALSE.
      ELSE IF( <a name="LSAME.269"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( JOBVSR, <span class="string">'V'</span> ) ) THEN
         IJOBVR = 2
         ILVSR = .TRUE.
      ELSE
         IJOBVR = -1
         ILVSR = .FALSE.
      END IF
<span class="comment">*</span><span class="comment">
</span>      WANTST = <a name="LSAME.277"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SORT, <span class="string">'S'</span> )
      WANTSN = <a name="LSAME.278"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SENSE, <span class="string">'N'</span> )
      WANTSE = <a name="LSAME.279"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SENSE, <span class="string">'E'</span> )
      WANTSV = <a name="LSAME.280"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SENSE, <span class="string">'V'</span> )
      WANTSB = <a name="LSAME.281"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SENSE, <span class="string">'B'</span> )
      LQUERY = ( LWORK.EQ.-1 .OR. LIWORK.EQ.-1 )
      IF( WANTSN ) THEN