1 INTEGER FUNCTION ISAMAX(N,SX,INCX)
2 * .. Scalar Arguments ..
3 INTEGER INCX,N
4 * ..
5 * .. Array Arguments ..
6 REAL SX(*)
7 * ..
8 *
9 * Purpose
10 * =======
11 *
12 * ISAMAX finds the index of element having max. absolute value.
13 *
14 * Further Details
15 * ===============
16 *
17 * jack dongarra, linpack, 3/11/78.
18 * modified 3/93 to return if incx .le. 0.
19 * modified 12/3/93, array(1) declarations changed to array(*)
20 *
21 * =====================================================================
22 *
23 * .. Local Scalars ..
24 REAL SMAX
25 INTEGER I,IX
26 * ..
27 * .. Intrinsic Functions ..
28 INTRINSIC ABS
29 * ..
30 ISAMAX = 0
31 IF (N.LT.1 .OR. INCX.LE.0) RETURN
32 ISAMAX = 1
33 IF (N.EQ.1) RETURN
34 IF (INCX.EQ.1) THEN
35 *
36 * code for increment equal to 1
37 *
38 SMAX = ABS(SX(1))
39 DO I = 2,N
40 IF (ABS(SX(I)).GT.SMAX) THEN
41 ISAMAX = I
42 SMAX = ABS(SX(I))
43 END IF
44 END DO
45 ELSE
46 *
47 * code for increment not equal to 1
48 *
49 IX = 1
50 SMAX = ABS(SX(1))
51 IX = IX + INCX
52 DO I = 2,N
53 IF (ABS(SX(IX)).GT.SMAX) THEN
54 ISAMAX = I
55 SMAX = ABS(SX(IX))
56 END IF
57 IX = IX + INCX
58 END DO
59 END IF
60 RETURN
61 END
2 * .. Scalar Arguments ..
3 INTEGER INCX,N
4 * ..
5 * .. Array Arguments ..
6 REAL SX(*)
7 * ..
8 *
9 * Purpose
10 * =======
11 *
12 * ISAMAX finds the index of element having max. absolute value.
13 *
14 * Further Details
15 * ===============
16 *
17 * jack dongarra, linpack, 3/11/78.
18 * modified 3/93 to return if incx .le. 0.
19 * modified 12/3/93, array(1) declarations changed to array(*)
20 *
21 * =====================================================================
22 *
23 * .. Local Scalars ..
24 REAL SMAX
25 INTEGER I,IX
26 * ..
27 * .. Intrinsic Functions ..
28 INTRINSIC ABS
29 * ..
30 ISAMAX = 0
31 IF (N.LT.1 .OR. INCX.LE.0) RETURN
32 ISAMAX = 1
33 IF (N.EQ.1) RETURN
34 IF (INCX.EQ.1) THEN
35 *
36 * code for increment equal to 1
37 *
38 SMAX = ABS(SX(1))
39 DO I = 2,N
40 IF (ABS(SX(I)).GT.SMAX) THEN
41 ISAMAX = I
42 SMAX = ABS(SX(I))
43 END IF
44 END DO
45 ELSE
46 *
47 * code for increment not equal to 1
48 *
49 IX = 1
50 SMAX = ABS(SX(1))
51 IX = IX + INCX
52 DO I = 2,N
53 IF (ABS(SX(IX)).GT.SMAX) THEN
54 ISAMAX = I
55 SMAX = ABS(SX(IX))
56 END IF
57 IX = IX + INCX
58 END DO
59 END IF
60 RETURN
61 END