function part2sim3csigma(L,sigma)
  truecapacitiessigma = [];
  approxcapacitiessigma = [];
  
  sigmavector=sigma:0.02:(sigma+2);
  for (sigmatry=sigmavector) 
    sigmatry
    N = L;
    [truecapacity,approx] = part2trueapproxcapacity2(L,N,sigmatry,1000);
    truecapacitiessigma = [ truecapacitiessigma truecapacity ];
    approxcapacitiessigma = [ approxcapacitiessigma approx ];
  end
  
  plot(1./(sigmavector.^2),truecapacitiessigma,'k+',1./(sigmavector.^2),approxcapacitiessigma,'ko');
  xlabel('\rho')
  legend('True capacitiy','Estimated capacity');