Help with 'fminsearch'

1 次查看（过去 30 天）

Niles Martinsen 2012-5-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/37920-help-with-fminsearch

I am fitting an exponential to my data using least squares, as in:

************************************************************

t = 0:7 ;
rel = [629 537 460 375 334 286 249 227];
fh = @(x,p) p(1) + p(2)*exp(-x./p(3))
errfh = @(p,x,y) sum((y(:)-fh(x(:),p)).^2)
p0 = [mean(rel) (max(rel)-min(rel)) (max(t) - min(t))/2];
P = fminsearch(errfh,p0,[],t,rel)
plot(t,rel,'bo',t,fh(t,P),'r-')

************************************************************

However, now I wish to increase MaxFunEvals. How can I do this, when I use fminsearch in this fashion?

Best, Niles.

5 个评论
显示 3更早的评论隐藏 3更早的评论

Oleg Komarov 2012-5-9

Usually oprimization routines all have a varargin input. Edit fminsearch or fminbnd.

Walter Roberson 2012-5-9

In 2008, Jos sometimes made mistakes.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（2 个）

Oleg Komarov 2012-5-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/37920-help-with-fminsearch#answer_47301

在 MATLAB Online 中打开

P = fminsearch(errfh,p0,optimset('MaxFunEvals',1000),t,rel)

Check the documentation for optimset

2 个评论
显示无隐藏无

Niles Martinsen 2012-5-9

I tried this out, but it did not have the desired effect unfortunately.

Oleg Komarov 2012-5-9

What do you mean it did not have the desired effect?

Try to reduce it to 10 or 50. Keep in mind it's a local solver.

请先登录，再进行评论。

Walter Roberson 2012-5-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/37920-help-with-fminsearch#answer_47302

You cannot increase MaxFunEvals when you use fminsearch in that fashion, as fminsearch takes a maximum of 3 inputs, not the 5 you are using. The function handle you provide to fminsearch must take exactly one argument. The initial guess follows the function handle, and the options structure (if provided) follows that.

http://www.mathworks.com/help/techdoc/ref/fminsearch.html