fof-visually-guided/elutils/+stats/sig4_invB.m

% y=sig4(beta,x)
% y0=beta(1);
% a=beta(2);
% x0=beta(3);
% b=beta(4);

function y=sig4_invB(beta,x)

y0=beta(1);
a=beta(2);
x0=beta(3);
b=1./beta(4);

y=y0+a./(1+ exp(-(x-x0)./b));