#include "ESMF_LapackBlas.inc" !> \brief \b DLASRT ! ! =========== DOCUMENTATION =========== ! ! Online html documentation available at ! http://www.netlib.org/lapack/explore-html/ ! !> \htmlonly !> Download DLASRT + dependencies !> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlasrt.f"> !> [TGZ]</a> !> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlasrt.f"> !> [ZIP]</a> !> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlasrt.f"> !> [TXT]</a> !> \endhtmlonly ! ! Definition: ! =========== ! ! SUBROUTINE DLASRT( ID, N, D, INFO ) ! ! .. Scalar Arguments .. ! CHARACTER ID ! INTEGER INFO, N ! .. ! .. Array Arguments .. ! DOUBLE PRECISION D( * ) ! .. ! ! !> \par Purpose: ! ============= !> !> \verbatim !> !> Sort the numbers in D in increasing order (if ID = 'I') or !> in decreasing order (if ID = 'D' ). !> !> Use Quick Sort, reverting to Insertion sort on arrays of !> size <= 20. Dimension of STACK limits N to about 2**32. !> \endverbatim ! ! Arguments: ! ========== ! !> \param[in] ID !> \verbatim !> ID is CHARACTER*1 !> = 'I': sort D in increasing order; !> = 'D': sort D in decreasing order. !> \endverbatim !> !> \param[in] N !> \verbatim !> N is INTEGER !> The length of the array D. !> \endverbatim !> !> \param[in,out] D !> \verbatim !> D is DOUBLE PRECISION array, dimension (N) !> On entry, the array to be sorted. !> On exit, D has been sorted into increasing order !> (D(1) <= ... <= D(N) ) or into decreasing order !> (D(1) >= ... >= D(N) ), depending on ID. !> \endverbatim !> !> \param[out] INFO !> \verbatim !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> \endverbatim ! ! Authors: ! ======== ! !> \author Univ. of Tennessee !> \author Univ. of California Berkeley !> \author Univ. of Colorado Denver !> \author NAG Ltd. ! !> \date November 2011 ! !> \ingroup auxOTHERcomputational ! ! ===================================================================== SUBROUTINE DLASRT( ID, N, D, INFO ) ! ! -- LAPACK computational routine (version 3.4.0) -- ! -- LAPACK is a software package provided by Univ. of Tennessee, -- ! -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- ! November 2011 ! ! .. Scalar Arguments .. CHARACTER ID INTEGER INFO, N ! .. ! .. Array Arguments .. DOUBLE PRECISION D( * ) ! .. ! ! ===================================================================== ! ! .. Parameters .. INTEGER SELECT PARAMETER ( SELECT = 20 ) ! .. ! .. Local Scalars .. INTEGER DIR, ENDD, I, J, START, STKPNT DOUBLE PRECISION D1, D2, D3, DMNMX, TMP ! .. ! .. Local Arrays .. INTEGER STACK( 2, 32 ) ! .. ! .. External Functions .. LOGICAL LSAME EXTERNAL LSAME ! .. ! .. External Subroutines .. EXTERNAL XERBLA ! .. ! .. Executable Statements .. ! ! Test the input paramters. ! INFO = 0 DIR = -1 IF( LSAME( ID, 'D' ) ) THEN DIR = 0 ELSE IF( LSAME( ID, 'I' ) ) THEN DIR = 1 END IF IF( DIR.EQ.-1 ) THEN INFO = -1 ELSE IF( N.LT.0 ) THEN INFO = -2 END IF IF( INFO.NE.0 ) THEN CALL XERBLA( 'DLASRT', -INFO ) RETURN END IF ! ! Quick return if possible ! IF( N.LE.1 ) & & RETURN ! STKPNT = 1 STACK( 1, 1 ) = 1 STACK( 2, 1 ) = N 10 CONTINUE START = STACK( 1, STKPNT ) ENDD = STACK( 2, STKPNT ) STKPNT = STKPNT - 1 IF( ENDD-START.LE.SELECT .AND. ENDD-START.GT.0 ) THEN ! ! Do Insertion sort on D( START:ENDD ) ! IF( DIR.EQ.0 ) THEN ! ! Sort into decreasing order ! DO 30 I = START + 1, ENDD DO 20 J = I, START + 1, -1 IF( D( J ).GT.D( J-1 ) ) THEN DMNMX = D( J ) D( J ) = D( J-1 ) D( J-1 ) = DMNMX ELSE GO TO 30 END IF 20 CONTINUE 30 CONTINUE ! ELSE ! ! Sort into increasing order ! DO 50 I = START + 1, ENDD DO 40 J = I, START + 1, -1 IF( D( J ).LT.D( J-1 ) ) THEN DMNMX = D( J ) D( J ) = D( J-1 ) D( J-1 ) = DMNMX ELSE GO TO 50 END IF 40 CONTINUE 50 CONTINUE ! END IF ! ELSE IF( ENDD-START.GT.SELECT ) THEN ! ! Partition D( START:ENDD ) and stack parts, largest one first ! ! Choose partition entry as median of 3 ! D1 = D( START ) D2 = D( ENDD ) I = ( START+ENDD ) / 2 D3 = D( I ) IF( D1.LT.D2 ) THEN IF( D3.LT.D1 ) THEN DMNMX = D1 ELSE IF( D3.LT.D2 ) THEN DMNMX = D3 ELSE DMNMX = D2 END IF ELSE IF( D3.LT.D2 ) THEN DMNMX = D2 ELSE IF( D3.LT.D1 ) THEN DMNMX = D3 ELSE DMNMX = D1 END IF END IF ! IF( DIR.EQ.0 ) THEN ! ! Sort into decreasing order ! I = START - 1 J = ENDD + 1 60 CONTINUE 70 CONTINUE J = J - 1 IF( D( J ).LT.DMNMX ) & & GO TO 70 80 CONTINUE I = I + 1 IF( D( I ).GT.DMNMX ) & & GO TO 80 IF( I.LT.J ) THEN TMP = D( I ) D( I ) = D( J ) D( J ) = TMP GO TO 60 END IF IF( J-START.GT.ENDD-J-1 ) THEN STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = START STACK( 2, STKPNT ) = J STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = J + 1 STACK( 2, STKPNT ) = ENDD ELSE STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = J + 1 STACK( 2, STKPNT ) = ENDD STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = START STACK( 2, STKPNT ) = J END IF ELSE ! ! Sort into increasing order ! I = START - 1 J = ENDD + 1 90 CONTINUE 100 CONTINUE J = J - 1 IF( D( J ).GT.DMNMX ) & & GO TO 100 110 CONTINUE I = I + 1 IF( D( I ).LT.DMNMX ) & & GO TO 110 IF( I.LT.J ) THEN TMP = D( I ) D( I ) = D( J ) D( J ) = TMP GO TO 90 END IF IF( J-START.GT.ENDD-J-1 ) THEN STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = START STACK( 2, STKPNT ) = J STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = J + 1 STACK( 2, STKPNT ) = ENDD ELSE STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = J + 1 STACK( 2, STKPNT ) = ENDD STKPNT = STKPNT + 1 STACK( 1, STKPNT ) = START STACK( 2, STKPNT ) = J END IF END IF END IF IF( STKPNT.GT.0 ) & & GO TO 10 RETURN ! ! End of DLASRT ! END