MATLAB: Undefined function for input arguments of type ‘double’

undefined function

I have this set of data
x=[0:0.01:1];
y=4- 3*x + sin(x*6*pi) + rand(1,101)/8;
plot(x,y,'ko','MarkerFaceColor','k');
and want to do a fit using fminsearch
hold on
b0=[2,-2,2,5];
b=fminsearch(@(b) doamne(b,x,y), b0);
yfit= b(1)+ b(2)*x + b(3)*sin(x*pi*b(4));
plot(x,yfit, '-b')
hold off
where
function d2=doamne(b,x,y)
c2=y- (b(1)+ b(2)*x)
d2=sum(c2.^2)
but I keep getting this error: "Undefined function 'doamne' for input arguments of type 'double'." I double checked that all my files are in the working folder and that the working folder is in the path list but the error persists.

Best Answer

Stefania - in the Command Window, type
 which doamne -all
to find the path to your doamne function. Perhaps you have named the m file for this function incorrectly, and so it cannot be found.
I was able to take the doamne function and copy and paste its code into a file named doamne.m and then could run the remainder of your code without error.
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