fsolve optimsiation in Matlab

Question

I wanted to know a specific thing about Matlab fsolve technique. As shown in the code, there are two non-linear equations. I can normally solve them but I want to optimise the process. It is observed that there is a common term 2*x(1)^2 - 3*x(2)^3 in both of these equations. The question is, can I declare a separate term for the common part and use the fsolve(as in the commented part)? If yes, can anyone please tell me the way to do.

function f = sym4(x)    
f(1)= 8*x(1)^2 -12*x(1)^3 +x(1)*x(2)+ x(2)^2-1;
f(2)= 2*x(1)^3 - 3*x(1)^4 +x(2)-3;

% z = 2*x(1)^2 - 3*x(2)^3;
% 
% f(1)= 4*z + x(2)^2 + x(1)*x(2) -1;
% f(2)= x*z +x(2)-3;


end

Your question, algebra, and code don't match up. Look again closely and pay attention to the indexes. — horchler
Thanks, for clarifying the doubt. Ya, I changed x to x(1) and it worked normally. — Sumanth Mehatha

m7913d m7913d · Accepted Answer · 2017-03-07T21:23:39

Yes, you can use intermediate variables, which may be somewhat faster because the common term is only evaluated once. As horchler pointed out, you should check your indexes.

fsolve optimsiation in Matlab

1 Answers