fitting a curve for multiple parameters and specific x values

Hi everyone, I am trying to fit a function to data points. I am starting off with two arrays of equal size lowfreq and lowmeanmale which contain x and y values respectively. The code goes like this:

x0 = [1,-1,0]; %initial parameters

x = fminsearch(@(x)myfun(x,lowfreq,lowmeanmale),x0); %here i try to find the minimum for three parameters x(1,2,3)

where myfun is defined as:

function f = myfun(x, frequency, pow) 

f = pow - x(1)*frequency.^x(2) + x(3); %here i find the difference between my data pow, and the function created by parameters for each x value of frequency

end

The error message goes like this:

Subscripted assignment dimension mismatch.

Error in fminsearch (line 191)

fv(:,1) = funfcn(x,varargin{:});

Anyone know what i am doing wrong?

Thanks for the help.

Answer 1

[Torsten]

f = sum((pow - (x(1)*frequency.^x(2) + x(3))).^2);

Best wishes

Torsten.

[Samson Chota]

Thank you so much.

Grettings, Samy