double complex function zdotcf(n,zx,incx,zy,incy)

c

c     forms the dot product of a vector.

c     jack dongarra, 3/11/78.

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

c

      double complex zx(*),zy(*),ztemp

      integer i,incx,incy,ix,iy,n

      ztemp = (0.0d0,0.0d0)

      zdotcf = (0.0d0,0.0d0)

      if(n.le.0)return

      if(incx.eq.1.and.incy.eq.1)go to 20

c

c        code for unequal increments or equal increments

c          not equal to 1

c

      ix = 1

      iy = 1

      if(incx.lt.0)ix = (-n+1)*incx + 1

      if(incy.lt.0)iy = (-n+1)*incy + 1

      do 10 i = 1,n

        ztemp = ztemp + dconjg(zx(ix))*zy(iy)

        ix = ix + incx

        iy = iy + incy

   10 continue

      zdotcf = ztemp

      return

c

c        code for both increments equal to 1

c

   20 do 30 i = 1,n

        ztemp = ztemp + dconjg(zx(i))*zy(i)

   30 continue

      zdotcf = ztemp

      return

      end