iseed = -1

!p.charsize=2


npts = 15


t = 0.1 + 0.8*findgen(npts)/npts

g = 9.81

 
x = 0.5*g*t^2 + 0.25*randomn(iseed,npts)


plotsym,0,1,/fill

plot,t,x,ps=1,xtit = 'Time [s]',ytit = 'Distance [m]'


b = transpose([t^2])
y = transpose(x)
psi = invert( transpose(b) ## b)
ans = psi ## transpose( b) ## y


npts = 100 
ti = findgen(npts)/npts

oplot,ti,ans[0]*ti^2



res = poly_fit(t,x,2)

oplot,ti,poly(ti,res),line=2

legend,['Parabola','Polynomial'],lines=[0,2],/top,/left,charsize=1.4





end