program myint

	dimension x1(4), y1(4), x2(5), y2(5)

	PI= 3.1415269

c Define the function.
	x1(1)= 0.5 
        y1(1)= 4.5
	x1(2)= 1.5 
        y1(2)= 6.2
	x1(3)= 2.5 
        y1(3)= 5.8
	x1(4)= 3.5
        y1(4)= 5.0

c Perform an interpolation on the first function
c to get the second function.
	epsil= -0.5
	delX= 1.0

	do i= 1, 3
	  x2(i)= float(i-1)
	  delY= y1(i+1) - y1(i)
	  y2(i)= y1(i) + epsil*delY/delX
	enddo
	x2(4)= 3.0 
	y2(4)= y1(4) + epsil*(y2(3)-y1(4))/0.5
	x2(5)= 4.0 
	y2(5)= y2(4) + k 

	call opngks

	call ezxy(x1, y1, 4, "Function I")	
	call clsgks

	end