Convert strings to array of function handles
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Hi, I'm using the opti platform and for NLP problems I need constraints in the following form:
nlcon = @(x) [ a(1)*x(1)^3 - b(2)*x(2);...
a(2)*x(2)^3 - b(3)*x(3);...
a(3)*x(3)^3 - b(1)*x(1)];
So I have small loop to generate these as strings:
a = [1 2 3];
b = [2 6 4 ];
pile = [];
for i = 1:length(a)
if i <= length(a)-1
text = [' a(' num2str(i) ')*x(' num2str(i) ')^3 - b(' num2str(i+1) ')*x(' num2str(i+1) ')'];
else
text = [' a(' num2str(i) ')*x(' num2str(i) ')^3 - b(1)*x(1)'];
end
pile = [pile; text];
end
And pile is the array of polynomials that i would like to form nlcon out of. Now if display or print pile and copy and past the result back into my script it works, but I'm certain there is a more elegant and efficient method. Cell arrays don't work, or at least I've had no success getting opti to accept them.
Kind regards,
ic_fly2
0 Comments
Answers (1)
José-Luis
on 30 Sep 2014
a = [1 2 3];
b = circshift(a,[0 -1]);
all_num = [a;a;b;b];
argument = sprintf('a(%i)*x(%i)^3 - b(%i)*x(%i)\r\n',all_num)
2 Comments
José-Luis
on 2 Oct 2014
I am not sure I follow. If you want an array of strings, then you could loop through every a value and generate the string as I show.
If you want to transform a string into a function, please look at str2func().
doc str2func
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