Logistic regression
data={{1,0},{1,1},{1,1},{2,0},{2,0},{2,1},{2,1},{2,1},{2,1},{3,1},
{3,1},{3,1},{3,1},{3,1}};
(* 成功機率 *)
pi[x_]:=1/(1+Exp[-(a+b*x)])
(* Likelihood function*)
obj=Apply[Times,pi[#[[1]]]^#[[2]]*(1-pi[#[[1]]])^(1-#[[2]])&/@data]
(* 求解a and b *)
FindMaximum[Log[obj],{a,0.1},{b,0.1}]
Plot[pi[x]/.FindMaximum[obj,{a,b}][[2]],{x,1,3},PlotRange->All]
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