Minimize using fminsearch?

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Brady Retzlaff 2015-11-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/252600-minimize-using-fminsearch

编辑： Geoff Hayes 2015-11-4

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...

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Brady Retzlaff 2015-11-4

编辑：Geoff Hayes 2015-11-4

在 MATLAB Online 中打开

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 2015-11-4

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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