LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
Loading...
Searching...
No Matches
slaord.f
Go to the documentation of this file.
1*> \brief \b SLAORD
2*
3* =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6* http://www.netlib.org/lapack/explore-html/
7*
8* Definition:
9* ===========
10*
11* SUBROUTINE SLAORD( JOB, N, X, INCX )
12*
13* .. Scalar Arguments ..
14* CHARACTER JOB
15* INTEGER INCX, N
16* ..
17* .. Array Arguments ..
18* REAL X( * )
19* ..
20*
21*
22*> \par Purpose:
23* =============
24*>
25*> \verbatim
26*>
27*> SLAORD sorts the elements of a vector x in increasing or decreasing
28*> order.
29*> \endverbatim
30*
31* Arguments:
32* ==========
33*
34*> \param[in] JOB
35*> \verbatim
36*> JOB is CHARACTER
37*> = 'I': Sort in increasing order
38*> = 'D': Sort in decreasing order
39*> \endverbatim
40*>
41*> \param[in] N
42*> \verbatim
43*> N is INTEGER
44*> The length of the vector X.
45*> \endverbatim
46*>
47*> \param[in,out] X
48*> \verbatim
49*> X is REAL array, dimension
50*> (1+(N-1)*INCX)
51*> On entry, the vector of length n to be sorted.
52*> On exit, the vector x is sorted in the prescribed order.
53*> \endverbatim
54*>
55*> \param[in] INCX
56*> \verbatim
57*> INCX is INTEGER
58*> The spacing between successive elements of X. INCX >= 0.
59*> \endverbatim
60*
61* Authors:
62* ========
63*
64*> \author Univ. of Tennessee
65*> \author Univ. of California Berkeley
66*> \author Univ. of Colorado Denver
67*> \author NAG Ltd.
68*
69*> \ingroup single_lin
70*
71* =====================================================================
72 SUBROUTINE slaord( JOB, N, X, INCX )
73*
74* -- LAPACK test routine --
75* -- LAPACK is a software package provided by Univ. of Tennessee, --
76* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
77*
78* .. Scalar Arguments ..
79 CHARACTER JOB
80 INTEGER INCX, N
81* ..
82* .. Array Arguments ..
83 REAL X( * )
84* ..
85*
86* =====================================================================
87*
88* .. Local Scalars ..
89 INTEGER I, INC, IX, IXNEXT
90 REAL TEMP
91* ..
92* .. External Functions ..
93 LOGICAL LSAME
94 EXTERNAL lsame
95* ..
96* .. Intrinsic Functions ..
97 INTRINSIC abs
98* ..
99* .. Executable Statements ..
100*
101 inc = abs( incx )
102 IF( lsame( job, 'I' ) ) THEN
103*
104* Sort in increasing order
105*
106 DO 20 i = 2, n
107 ix = 1 + ( i-1 )*inc
108 10 CONTINUE
109 IF( ix.EQ.1 )
110 $ GO TO 20
111 ixnext = ix - inc
112 IF( x( ix ).GT.x( ixnext ) ) THEN
113 GO TO 20
114 ELSE
115 temp = x( ix )
116 x( ix ) = x( ixnext )
117 x( ixnext ) = temp
118 END IF
119 ix = ixnext
120 GO TO 10
121 20 CONTINUE
122*
123 ELSE IF( lsame( job, 'D' ) ) THEN
124*
125* Sort in decreasing order
126*
127 DO 40 i = 2, n
128 ix = 1 + ( i-1 )*inc
129 30 CONTINUE
130 IF( ix.EQ.1 )
131 $ GO TO 40
132 ixnext = ix - inc
133 IF( x( ix ).LT.x( ixnext ) ) THEN
134 GO TO 40
135 ELSE
136 temp = x( ix )
137 x( ix ) = x( ixnext )
138 x( ixnext ) = temp
139 END IF
140 ix = ixnext
141 GO TO 30
142 40 CONTINUE
143 END IF
144 RETURN
145*
146* End of SLAORD
147*
148 END
subroutine slaord(JOB, N, X, INCX)
SLAORD
Definition: slaord.f:73