-- Compton Scattering of Quasi-Real Virtual Photons at LEP -- arxiv.org/abs/hep-ex/0504012 -- Data from Table 4, page 11. N = 12 -- number of observations -- x is cos(theta) x = ( -0.74, -0.60, -0.47, -0.34, -0.20, -0.07, 0.06, 0.20, 0.33, 0.46, 0.60, 0.73) -- y is cross section y = ( 13380, 7720, 6360, 4600, 4310, 3700, 3640, 3340, 3500, 3010, 3310, 3330) y = y "picobarn" "Observed cross section per bin" y pi = float(pi) -- use numerical value of pi alpha = 0.0072973525693 hbar = 6.582119569 10^(-25) "GeV" "second" c = 299792458 "meter" / "second" s = 40 "GeV"^2 C = pi/s alpha^2 (hbar c)^2 10^40 "picobarn" / "meter"^2 yhat = zero(N) for(k,1,N, yhat[k] = C ((x[k]+1)/2 + 2/(x[k]+1))) "Predicted cross section" yhat "Coefficient of determination (R squared)" ybar = sum(y) / dim(y) RSS = sum((y - yhat)^2) -- residual sum of squares TSS = sum((y - ybar)^2) -- total sum of squares 1 - RSS / TSS Run