[問題] matlab求最大概似函數已回收

看板MATLAB作者contente (妹妹)時間16年前 (2009/03/22 11:16)推噓0(0推 0噓 0→)

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我想用兩個變數 B S ，估計七個參數theta1~theta7 其中B和S各有四天的資料最大概似函數是用函數取log再加上負號，求極小值的方式求算我是新手，請幫我看看哪裡出了問題? 不好意思這是我的碩士論文，所以概似函數非常的長謝謝大家 1.M-FILE: function like=Qn(theta) global B S eps1=B; eps2=S; like=mean((9*log(prod(1:eps1))+9*log(prod(1:eps2))-3*log(1-theta(2))... -3*log(theta(2))-6*log(theta(1))-3*log(1-theta(1))-6*log(theta(3))... -3*log(1-theta(3))-3*log(1-theta(4))-3*log(theta(4))... +(18*theta(5)+6*theta(6)+6*theta(7))-2*eps1*log(theta(5)+theta(7))... -eps1*log(theta(5)+theta(6))-2*eps1*log(theta(5))... -eps1*log(theta(5)+theta(6)+theta(7))-2*eps1*log(theta(5))... -eps1*log(theta(5)+theta(6))... -4*eps2*log(theta(5))-2*eps2*log(theta(5)+theta(7))... -2*eps2*log(theta(5)+theta(6))... -eps2*log(theta(5)+theta(6)+theta(7))),1); 2.COMMAND WINDOW: >> global B S >> B=[125 476 543 822]; >> S=[53 235 490 566]; >> theta0=[1;1;1;1;5;5;5]; >> f=@Qn; >> [theta_ml,fval,exitflag,output]=fminsearch(f,theta0); 3.顯示的結果: Warning: Colon operands must be real scalars. Warning: Log of zero. > In Qn at 5 In fminsearch at 175 ??? Subscripted assignment dimension mismatch. Error in ==> fminsearch at 175 fv(:,1) = funfcn(x,varargin{:}); 謝謝大家耐心的看完!! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 219.70.216.65