REAL*8 function dzamaxf(n,zx,incx)

c

c     finds the index of element having max. absolute value.

c     jack dongarra, 1/15/85.

c     modified 3/93 to return if incx .le. 0.

c     modified 12/3/93, array(1) declarations changed to array(*)

c

      COMPLEX*16 zx(*)

      integer i,incx,ix,n

      double precision dcabs1

c

      dzamaxf = 0.

      if( n.lt.1 .or. incx.le.0 )return

      dzamaxf = dcabs1(zx(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

      dzamaxf = dcabs1(zx(1))

      ix = ix + incx

      do 10 i = 2,n

         if(dcabs1(zx(ix)).le.dzamaxf) go to 5

         dzamaxf = i

         dzamaxf = dcabs1(zx(ix))

    5    ix = ix + incx

   10 continue

      return

c

c        code for increment equal to 1

c

   20 dzamaxf = dcabs1(zx(1))

      do 30 i = 2,n

         if(dcabs1(zx(i)).le.dzamaxf) go to 30

         dzamaxf = i

         dzamaxf = dcabs1(zx(i))

   30 continue

      return

      end