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Diff for /rpl/lapack/lapack/dlaed4.f between versions 1.11 and 1.19

version 1.11, 2012/12/14 12:30:22 version 1.19, 2023/08/07 08:38:53
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 *> \brief \b DLAED4 used by sstedc. Finds a single root of the secular equation.  *> \brief \b DLAED4 used by DSTEDC. Finds a single root of the secular equation.
 *  *
 *  =========== DOCUMENTATION ===========  *  =========== DOCUMENTATION ===========
 *  *
 * Online html documentation available at   * Online html documentation available at
 *            http://www.netlib.org/lapack/explore-html/   *            http://www.netlib.org/lapack/explore-html/
 *  *
 *> \htmlonly  *> \htmlonly
 *> Download DLAED4 + dependencies   *> Download DLAED4 + dependencies
 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlaed4.f">   *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlaed4.f">
 *> [TGZ]</a>   *> [TGZ]</a>
 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlaed4.f">   *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlaed4.f">
 *> [ZIP]</a>   *> [ZIP]</a>
 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlaed4.f">   *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlaed4.f">
 *> [TXT]</a>  *> [TXT]</a>
 *> \endhtmlonly   *> \endhtmlonly
 *  *
 *  Definition:  *  Definition:
 *  ===========  *  ===========
 *  *
 *       SUBROUTINE DLAED4( N, I, D, Z, DELTA, RHO, DLAM, INFO )  *       SUBROUTINE DLAED4( N, I, D, Z, DELTA, RHO, DLAM, INFO )
 *   *
 *       .. Scalar Arguments ..  *       .. Scalar Arguments ..
 *       INTEGER            I, INFO, N  *       INTEGER            I, INFO, N
 *       DOUBLE PRECISION   DLAM, RHO  *       DOUBLE PRECISION   DLAM, RHO
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 *       .. Array Arguments ..  *       .. Array Arguments ..
 *       DOUBLE PRECISION   D( * ), DELTA( * ), Z( * )  *       DOUBLE PRECISION   D( * ), DELTA( * ), Z( * )
 *       ..  *       ..
 *    *
 *  *
 *> \par Purpose:  *> \par Purpose:
 *  =============  *  =============
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 *> \param[out] DELTA  *> \param[out] DELTA
 *> \verbatim  *> \verbatim
 *>          DELTA is DOUBLE PRECISION array, dimension (N)  *>          DELTA is DOUBLE PRECISION array, dimension (N)
 *>         If N .GT. 2, DELTA contains (D(j) - lambda_I) in its  j-th  *>         If N > 2, DELTA contains (D(j) - lambda_I) in its  j-th
 *>         component.  If N = 1, then DELTA(1) = 1. If N = 2, see DLAED5  *>         component.  If N = 1, then DELTA(1) = 1. If N = 2, see DLAED5
 *>         for detail. The vector DELTA contains the information necessary  *>         for detail. The vector DELTA contains the information necessary
 *>         to construct the eigenvectors by DLAED3 and DLAED9.  *>         to construct the eigenvectors by DLAED3 and DLAED9.
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 *  Authors:  *  Authors:
 *  ========  *  ========
 *  *
 *> \author Univ. of Tennessee   *> \author Univ. of Tennessee
 *> \author Univ. of California Berkeley   *> \author Univ. of California Berkeley
 *> \author Univ. of Colorado Denver   *> \author Univ. of Colorado Denver
 *> \author NAG Ltd.   *> \author NAG Ltd.
 *  
 *> \date September 2012  
 *  *
 *> \ingroup auxOTHERcomputational  *> \ingroup auxOTHERcomputational
 *  *
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 *  =====================================================================  *  =====================================================================
       SUBROUTINE DLAED4( N, I, D, Z, DELTA, RHO, DLAM, INFO )        SUBROUTINE DLAED4( N, I, D, Z, DELTA, RHO, DLAM, INFO )
 *  *
 *  -- LAPACK computational routine (version 3.4.2) --  *  -- LAPACK computational routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --  *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--  *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 *     September 2012  
 *  *
 *     .. Scalar Arguments ..  *     .. Scalar Arguments ..
       INTEGER            I, INFO, N        INTEGER            I, INFO, N
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          IF( C.LT.ZERO )           IF( C.LT.ZERO )
      $      C = ABS( C )       $      C = ABS( C )
          IF( C.EQ.ZERO ) THEN           IF( C.EQ.ZERO ) THEN
 *          ETA = B/A  *           ETA = B/A
 *           ETA = RHO - TAU  *           ETA = RHO - TAU
             ETA = DLTUB - TAU  *           ETA = DLTUB - TAU
   *
   *           Update proposed by Li, Ren-Cang:
               ETA = -W / ( DPSI+DPHI )
          ELSE IF( A.GE.ZERO ) THEN           ELSE IF( A.GE.ZERO ) THEN
             ETA = ( A+SQRT( ABS( A*A-FOUR*B*C ) ) ) / ( TWO*C )              ETA = ( A+SQRT( ABS( A*A-FOUR*B*C ) ) ) / ( TWO*C )
          ELSE           ELSE
Removed from v.1.11  
changed lines
  Added in v.1.19

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