Optimization
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From: JohnV on 8 Jul 2010 09:15 I am having trouble using the optimization commands. I defined the function m.file function [z]=Meshat(x,r) z=80*r^2*exp(-x^2-0.3*r^2); end then, k=[4.23,3.56]; F=fminsearch(@meshat,k); and received the following error messages, ??? Input argument "r" is undefined. Error in ==> Meshat at 4 z=80*r^2*exp(-x^2-0.3*r^2); Error in ==> fminsearch at 205 fv(:,1) = funfcn(x,varargin{:}); Error in ==> optimization at 3 F=fminsearch(@meshat,k); Can someone correct my error?
From: Steven Lord on 8 Jul 2010 13:26
"JohnV" <johnvalica(a)hotmail.com> wrote in message news:1355149227.91194.1278609347154.JavaMail.root(a)gallium.mathforum.org... >I am having trouble using the optimization commands. > I defined the function m.file > > function [z]=Meshat(x,r) > z=80*r^2*exp(-x^2-0.3*r^2); > end > > then, > > k=[4.23,3.56]; > F=fminsearch(@meshat,k); Are you expecting FMINSEARCH to call your function with two inputs, a scalar for x (whose initial guess value is 4.23) and a scalar for r (whose initial guess value is 3.56)? If so, take a look at what the documentation page for FMINSEARCH and says about how FMINSEARCH expects the function you pass in to behave. http://www.mathworks.com/access/helpdesk/help/techdoc/ref/fminsearch.html The easiest way to fix this is to modify your function: function [z]=Meshat(myparams) x = myparams(1); r = myparams(2); z=80*r^2*exp(-x^2-0.3*r^2); end Then FMINSEARCH will call your function with a 2-element vector, your function will break that vector into the two individual parameters, and it will then evaluate your function using those two parameters. *snip* -- Steve Lord slord(a)mathworks.com comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ To contact Technical Support use the Contact Us link on http://www.mathworks.com |