vonmises distribution fit with matlab

multipeak_vonmises.m

twopeakVonmises = @(v, x) ...
	v(1) + v(2)*exp(-1* ((x*pi/180) - v(3)).^2 * (1/(2*v(4)^2))) ...
	     + v(5)*exp(-1* ((x*pi/180) - v(3)+v(6)).^2 * (1/(2*v(4)^2)));		 
options = optimoptions('fmincon', 'MaxIter', 100000,'GradObj','off');

for i = 1:size(stimResp.meanVal, 1)
	tmp = (stimResp.meanVal(i,1:end-1)-1);
	
	fcn = @(v) sum(abs((twopeakVonmises(v,ORvar) - tmp)));
	v(1) = min(tmp);	           % baseline
	[v(2), maxidx] = max(tmp);	 % amplitude
	v(3) = ORvar(maxidx)*pi/180; % peak 1
	v(4) = pi/4;                 % width
	v(5) = v(2);                % amplitude 2
	
	if v(3) > pi
		v(6) = pi;                % peak val
	else
		v(6) = -pi;               % peak val
	end
	
	[s,f(i),flag(i),lamb(i)] = fmincon(fcn, [v(1); v(2); v(3); v(4); v(5); v(6)], ...
		[],[],[],[],[],[],[],options);		 
	figure;
	subplot(121)
	plot(ORvar, tmp, 'o'); hold on;
	plot(x, twopeakVonmises(s,x), '-r')
	subplot(122)
	polar([ORvar 360]*pi/180, [tmp tmp(1)])
end