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integer function idamax(n,dx,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
double precision dx(1),dmax
integer i,incx,ix,n
c
idamax = 0
if( n .lt. 1 ) return
idamax = 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
dmax = dabs(dx(ix))
ix = ix + incx
do 10 i = 2,n
if(dabs(dx(ix)).le.dmax) go to 5
idamax = i
dmax = dabs(dx(ix))
5 ix = ix + incx
10 continue
return
c
c code for increment equal to 1
c
20 dmax = dabs(dx(1))
do 30 i = 2,n
if(dabs(dx(i)).le.dmax) go to 30
idamax = i
dmax = dabs(dx(i))
30 continue
return
end
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