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SUBROUTINE DLAORD( JOB, N, X, INCX )
*
* -- LAPACK auxiliary routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* February 29, 1992
*
* .. Scalar Arguments ..
CHARACTER JOB
INTEGER INCX, N
* ..
* .. Array Arguments ..
DOUBLE PRECISION X( * )
* ..
*
* Purpose
* =======
*
* DLAORD sorts the elements of a vector x in increasing or decreasing
* order.
*
* Arguments
* =========
*
* JOB (input) CHARACTER
* = 'I': Sort in increasing order
* = 'D': Sort in decreasing order
*
* N (input) INTEGER
* The length of the vector X.
*
* X (input/output) DOUBLE PRECISION array, dimension
* (1+(N-1)*INCX)
* On entry, the vector of length n to be sorted.
* On exit, the vector x is sorted in the prescribed order.
*
* INCX (input) INTEGER
* The spacing between successive elements of X. INCX >= 0.
*
* =====================================================================
*
* .. Local Scalars ..
INTEGER I, INC, IX, IXNEXT
DOUBLE PRECISION TEMP
* ..
* .. External Functions ..
LOGICAL LSAME
EXTERNAL LSAME
* ..
* .. Intrinsic Functions ..
INTRINSIC ABS
* ..
* .. Executable Statements ..
*
INC = ABS( INCX )
IF( LSAME( JOB, 'I' ) ) THEN
*
* Sort in increasing order
*
DO 20 I = 2, N
IX = 1 + ( I-1 )*INC
10 CONTINUE
IF( IX.EQ.1 )
$ GO TO 20
IXNEXT = IX - INC
IF( X( IX ).GT.X( IXNEXT ) ) THEN
GO TO 20
ELSE
TEMP = X( IX )
X( IX ) = X( IXNEXT )
X( IXNEXT ) = TEMP
END IF
IX = IXNEXT
GO TO 10
20 CONTINUE
*
ELSE IF( LSAME( JOB, 'D' ) ) THEN
*
* Sort in decreasing order
*
DO 40 I = 2, N
IX = 1 + ( I-1 )*INC
30 CONTINUE
IF( IX.EQ.1 )
$ GO TO 40
IXNEXT = IX - INC
IF( X( IX ).LT.X( IXNEXT ) ) THEN
GO TO 40
ELSE
TEMP = X( IX )
X( IX ) = X( IXNEXT )
X( IXNEXT ) = TEMP
END IF
IX = IXNEXT
GO TO 30
40 CONTINUE
END IF
RETURN
*
* End of DLAORD
*
END
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