function ss = algaess(theta,data) % algae sum-of-squares function time = data.ydata(:,1); ydata = data.ydata(:,2:end); xdata = data.xdata; % 3 last parameters are the initial states y0 = theta(end-2:end); ymodel = algaefun(time,theta,y0,xdata); ss = sum((ymodel - ydata).^2);