program graph4
   implicit none
   call init
   call viewport(0.2,0.2,0.8,0.8)
   call xyworld(0.0,0.0,1.0,4.0)
   call frame
   call plotd
   call fin
   stop
   end

real function f(x)
   implicit none
   real(4) x
   f=2.0*exp(4.0*x)
   return
   end

subroutine plotd
   implicit none
   real(4),dimension(0:20)::x1,y1
   integer i
   integer,parameter::n=20
   real(4) f
   do i=0,n
      x1(i)=real(i)/real(n)
      y1(i)=f(x1(i))
   end do
   do i=0,n
      y1(i)=alog10(y1(i))
   end do
   call linewidth(1.5)
   call linety(1)
   call setgray(0.0)
   call plot(x1(0),y1(0),3)
   do i=1,n-2
      call spline(x1(i-1),y1(i-1),x1(i),y1(i),x1(i+1),y1(i+1),x1(i+2),y1(i+2),-1)
   end do
   call spline(x1(n-3),y1(n-3),x1(n-2),y1(n-2),x1(n-1),y1(n-1),x1(n),y1(n),0)
   call spline(x1(n-3),y1(n-3),x1(n-2),y1(n-2),x1(n-1),y1(n-1),x1(n),y1(n),1)
   call stroke
   return
   end

subroutine frame
   implicit none
   real(4) x,y,dx,dy
   integer,parameter::nx=1,ny=4
   integer ix,iy,ixx,iyy
   call linewidth(1.0)
   call rect(0.0,0.0,1.0,4.0)
   call stroke
   do ix=0,nx-1
      call setgray(0.5)
      x=real(ix)
      dy=4.0
      if(ix/=0)then
         call plot(x,0.0,3)
         call plot(x,dy,2)
         call stroke
      end if
      do ixx=1,9
         call setgray(0.8)
         x=real(ixx)/10.0
         call plot(x,0.0,3)
         call plot(x,dy,2)
         call stroke
      end do
   end do
   do iy=0,ny-1
      call setgray(0.5)
      y=real(iy)
      dx=1.0
      if(iy/=0)then
         call plot(0.0,y,3)
         call plot(dx,y,2)
         call stroke
      end if
      do iyy=2,9
         call setgray(0.8)
         y=real(iy)+alog10(real(iyy))
         call plot(0.0,y,3)
         call plot(dx,y,2)
         call stroke
      end do
   end do
   call setgray(0.0)
   call textx(0.75,0.0,'x')
   call textx(0.0,0.02,'0')
   call textx(0.5,0.02,'0.5')
   call textx(1.0,0.02,'1')
   call texty(0.0,3.5,'y')
   call texty(0.0,0.0,'1')
   call texty(0.0,1.0,'10')
   call texty(0.0,2.0,'100')
   call texty(0.0,3.0,'1000')
   call texty(0.0,4.0,'10000')
   return
   end