1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
integer function isamax(n,sx,incx)
c
c finds the index of element having max. absolute value.
c jack dongarra, linpack, 3/11/78.
c modified to correct problem with negative increment, 8/21/90.
c
real sx(1),smax
integer i,incx,ix,n
c
isamax = 0
if( n .lt. 1 ) return
isamax = 1
if(n.eq.1)return
if(incx.eq.1)go to 20
c
c code for increment not equal to 1
c
ix = 1
if(incx.lt.0)ix = (-n+1)*incx + 1
smax = abs(sx(ix))
ix = ix + incx
do 10 i = 2,n
if(abs(sx(ix)).le.smax) go to 5
isamax = i
smax = abs(sx(ix))
5 ix = ix + incx
10 continue
return
c
c code for increment equal to 1
c
20 smax = abs(sx(1))
do 30 i = 2,n
if(abs(sx(i)).le.smax) go to 30
isamax = i
smax = abs(sx(i))
30 continue
return
end
|
