function plotFICurveFit(fi, fi_error, contrasts, fit_parameter, filename)

plotFICurve(fi, fi_error, contrasts, '')
fit = boltzmannModel(fit_parameter, min(contrasts):0.1:max(contrasts));
hold on 
plot(min(contrasts):0.1:max(contrasts), fit, 'displayname', 'Boltzmann fit')
legend('Location', 'northwest')
saveas(gcf, filename, 'pdf')