integer function isamaxf(n,sx,incx)
c
c finds the index of element having max. 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(*),smax
integer i,incx,ix,n
c
isamaxf = 0
if( n.lt.1 .or. incx.le.0 ) return
isamaxf = 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
smax = abs(sx(1))
ix = ix + incx
do 10 i = 2,n
if(abs(sx(ix)).le.smax) go to 5
isamaxf = 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
isamaxf = i
smax = abs(sx(i))
30 continue
return
end