tahoma2d/thirdparty/openblas/xianyi-OpenBLAS-e6e87a2/reference/isaminf.f
2016-03-24 02:47:04 +09:00

39 lines
917 B
Fortran

integer function isaminf(n,sx,incx)
c
c finds the index of element having min. absolute value.
c jack dongarra, linpack, 3/11/78.
c modified 3/93 to return if incx .le. 0.
c modified 12/3/93, array(1) declarations changed to array(*)
c
real sx(*),smin
integer i,incx,ix,n
c
isaminf = 0
if( n.lt.1 .or. incx.le.0 ) return
isaminf = 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
smin = abs(sx(1))
ix = ix + incx
do 10 i = 2,n
if(abs(sx(ix)).ge.smin) go to 5
isaminf = i
smin = abs(sx(ix))
5 ix = ix + incx
10 continue
return
c
c code for increment equal to 1
c
20 smin = abs(sx(1))
do 30 i = 2,n
if(abs(sx(i)).ge.smin) go to 30
isaminf = i
smin = abs(sx(i))
30 continue
return
end