Error message using function fminunc

Question

Orongo 2018-4-11

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/394204-error-message-using-function-fminunc

关闭： Orongo 2018-4-12

Hi, I'm using the function fminunc to find my least square error. Unfortunately I get the error message

      Error using fminusub (line 16)
      Objective function is undefined at initial point. Fminunc cannot continue.
      Error in fminunc (line 457)
         [x,FVAL,GRAD,HESSIAN,EXITFLAG,OUTPUT] = fminusub(funfcn,x, ...

I understand the error can be caused by an inf or nan value, however I don't this applicable to me (??). My program for generation born 1938 looks like (the other generations result in same error message):

fun_1938=@(param)f_Makeham(param, mu_perks_1938, 1938);
param0_1938 = [2.06441912000572E-07/1000,0.197642212387667/100000,1.23947876070978/10];
[param_1938, fval_1938]=fminunc(fun_1938,param0_1938);

where

function res = f_Makeham(param,mu_perks,year)
a0=param(1);
b0=param(2);
c0=param(3);
if year == 1938
    x=(77.5:1:106.5)';
elseif year==1945
    x=(70.5:1:106.5)';
elseif year==1955
    x=(65.5:1:106.5)';
end
res=sum((a0+b0*exp(c0*x)-mu_perks).^2);

What is causing the error message? How can I error track this?

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Walter Roberson 2018-4-12

Possibly mu_perks_1938 is not defined.

此问题已关闭。

Answer 1

Alan Weiss 2018-4-11

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/394204-error-message-using-function-fminunc#answer_314596

The error is clear. Try to evaluate fun_1938(param0_1938) and you will find that it throws an error. Investigate the error using standard MATLAB debugging.

Alan Weiss

MATLAB mathematical toolbox documentation