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-version 1.4, 2010/08/06 15:32:27
+version 1.19, 2023/08/07 08:38:55
  Line 1
+ *> \brief \b DLAPY2 returns sqrt(x2+y2).
+ *
+ *  =========== DOCUMENTATION ===========
+ *
+ * Online html documentation available at
+ *            http://www.netlib.org/lapack/explore-html/
+ *
+ *> \htmlonly
+ *> Download DLAPY2 + dependencies
+ *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlapy2.f">
+ *> [TGZ]</a>
+ *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlapy2.f">
+ *> [ZIP]</a>
+ *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlapy2.f">
+ *> [TXT]</a>
+ *> \endhtmlonly
+ *
+ *  Definition:
+ *  ===========
+ *
+ *       DOUBLE PRECISION FUNCTION DLAPY2( X, Y )
+ *
+ *       .. Scalar Arguments ..
+ *       DOUBLE PRECISION   X, Y
+ *       ..
+ *
+ *
+ *> \par Purpose:
+ *  =============
+ *>
+ *> \verbatim
+ *>
+ *> DLAPY2 returns sqrt(x**2+y**2), taking care not to cause unnecessary
+ *> overflow and unnecessary underflow.
+ *> \endverbatim
+ *
+ *  Arguments:
+ *  ==========
+ *
+ *> \param[in] X
+ *> \verbatim
+ *>          X is DOUBLE PRECISION
+ *> \endverbatim
+ *>
+ *> \param[in] Y
+ *> \verbatim
+ *>          Y is DOUBLE PRECISION
+ *>          X and Y specify the values x and y.
+ *> \endverbatim
+ *
+ *  Authors:
+ *  ========
+ *
+ *> \author Univ. of Tennessee
+ *> \author Univ. of California Berkeley
+ *> \author Univ. of Colorado Denver
+ *> \author NAG Ltd.
+ *
+ *> \ingroup OTHERauxiliary
+ *
+ *  =====================================================================
        DOUBLE PRECISION FUNCTION DLAPY2( X, Y )
  *
- *  -- LAPACK auxiliary routine (version 3.2) --
+ *  -- LAPACK auxiliary routine --
  *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
  *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
- *     November 2006
  *
  *     .. Scalar Arguments ..
        DOUBLE PRECISION   X, Y
  *     ..
  *
- *  Purpose
- *  =======
- *
- *  DLAPY2 returns sqrt(x**2+y**2), taking care not to cause unnecessary
- *  overflow.
- *
- *  Arguments
- *  =========
- *
- *  X       (input) DOUBLE PRECISION
- *  Y       (input) DOUBLE PRECISION
- *          X and Y specify the values x and y.
- *
  *  =====================================================================
  *
  *     .. Parameters ..
- Line 31
+ Line 78
        PARAMETER          ( ONE = 1.0D0 )
  *     ..
  *     .. Local Scalars ..
-       DOUBLE PRECISION   W, XABS, YABS, Z
+       DOUBLE PRECISION   W, XABS, YABS, Z, HUGEVAL
+       LOGICAL            X_IS_NAN, Y_IS_NAN
+ *     ..
+ *     .. External Functions ..
+       LOGICAL            DISNAN
+       EXTERNAL           DISNAN
+ *     ..
+ *     .. External Subroutines ..
+       DOUBLE PRECISION   DLAMCH
  *     ..
  *     .. Intrinsic Functions ..
        INTRINSIC          ABS, MAX, MIN, SQRT
  *     ..
  *     .. Executable Statements ..
  *
-       XABS = ABS( X )
+       X_IS_NAN = DISNAN( X )
-       YABS = ABS( Y )
+       Y_IS_NAN = DISNAN( Y )
-       W = MAX( XABS, YABS )
+       IF ( X_IS_NAN ) DLAPY2 = X
-       Z = MIN( XABS, YABS )
+       IF ( Y_IS_NAN ) DLAPY2 = Y
-       IF( Z.EQ.ZERO ) THEN
+       HUGEVAL = DLAMCH( 'Overflow' )
-          DLAPY2 = W
+ *
-       ELSE
+       IF ( .NOT.( X_IS_NAN.OR.Y_IS_NAN ) ) THEN
-          DLAPY2 = W*SQRT( ONE+( Z / W )**2 )
+          XABS = ABS( X )
+          YABS = ABS( Y )
+          W = MAX( XABS, YABS )
+          Z = MIN( XABS, YABS )
+          IF( Z.EQ.ZERO .OR. W.GT.HUGEVAL ) THEN
+             DLAPY2 = W
+          ELSE
+             DLAPY2 = W*SQRT( ONE+( Z / W )**2 )
+          END IF
        END IF
        RETURN
  *

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