clear
window 0
defaults
!
x = [0:10]
y = 2*x^2-3*x+50 + 75*ran(x)
generate xx 0,,10,100
set plotsymbol -10
set plotsymbolcolor red
graph x y
set plotsymbol 0
set curvecolor black
t = [0;0.001;0.01;0.1]
do i = [1:len(t)]
 set tension t[i]
 set curvecolor -(i+6)
 display 'Using tension = '//rchar(t[i])
 graph\overlay xx smooth(x,y,xx)
enddo
replot