[params,f] =
FitNakaRushton(contrast,response,[params0])
Find the parameters that best fit the data. If the initial guess
isn't good, this can get stuck in local minima.
8/1/05 dhb, pr Wrote it.
8/2/07 dhb Change argument order.
Psychtoolbox/Psychometric/FitNakaRushton.m