Minimize using fminsearch?

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Brady Retzlaff
Brady Retzlaff on 3 Nov 2015
Edited: Geoff Hayes on 4 Nov 2015
The question is this
Use fminsearch to minimize the function you wrote above, using an initial guess of your choosing. Use the resulting c1 and c2 to evaluate f(x) at the values of x from exercise 2, storing the result as y. Plot the data and your curve (using x and y) to verify the fit. Once verified, save the first 10 elements of y
My code is:
objFunc = @(c) ( errFunc(c) );
C = fminsearch(objFunc, [1.0;1.0]);
for j=1:n
y(j) = C(1)*sin(x(j)+C(2));
end
What am i doing wrong??? i'm sure my errFunc is correct...
  3 Comments
Brady Retzlaff
Brady Retzlaff on 4 Nov 2015
Edited: Geoff Hayes on 4 Nov 2015
if true
% code
end
my effFunc is as follows...
function [e] = errFunc(c)
data2x =
data2y =
e = 0.0;
M=length(data2x);
for j=1:M
e = e + (c(1)*sin(data2x(j)+c(2)) - data2y(j))^2;
end
end
I know that it's incorrect because when i plot it next to the data im trying to fit, the graph is not even close... but im not getting an error
Star Strider
Star Strider on 4 Nov 2015
You need to use fminsearch to minimise the sum of squares difference between your objective function (which is a function only of your parameters and your independent variable) and your dependent variable. I usually do this with two functions, the objective function and the sum-of-squares cost function, and minimise the cost function.

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