damaxf.f

REAL*8 function damaxf(n,dx,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
double precision dx(*)
integer i,incx,ix,n
c
 damaxf =0
if( n.lt.1.or. incx.le.0 ) return

if(incx.eq.1)go to20
c
c code for increment not equal to 1
c
 ix =1
 damaxf = dabs(dx(1))
 ix = ix + incx
do10 i =2,n
if(dabs(dx(ix)).le.damaxf) go to5
 damaxf = dabs(dx(ix))
5 ix = ix + incx
10continue
return
c
c code for increment equal to 1
c
20 damaxf = dabs(dx(1))
do30 i =2,n
if(dabs(dx(i)).le.damaxf) go to30
 damaxf = dabs(dx(i))
30continue
return
 end