MATLAB: Minimize the error between calculated values and experimental results

minimization

Hello, I am writing the following code to minimize the error between calculated values and experimental results:
K=[1 2 2.8 3.3 3.5 3.6]; %some data to test
v = sym('v',[1 2]);
a = v(1); b = v(2);
e=[1 2 3 4 5 6]
eo=2
for i=1:1:6
    D(i)=@(v)a*(e(i)-eo)^b
    E(i)=e(i)*(1-D(i));
    R(i)=(K(i)-E(i))^2;
end
RM=0
for i=1:1:6
    RM=RM+R(i)
end
RMS=(RM)^(1/2)
v = [0.12 2];
c=fminsearch(RMS,v)
Its showing error. Can you please help to solve the issue.

Best Answer

Hi, I understand you are trying to minimize error for given set of data. The error in your code is due the fact that the function fminsearch takes function handle as input, instead of sym. First you need to convert the ‘RMS’ to function handle using matlabFunction and then compute the minimum. Here is the modified code for it.
clear all;
clc;
K=[1 2 2.8 3.3 3.5 3.6]; %some data to test
v = sym('v',[1 2]);
a = v(1); b = v(2);
e=[1 2 3 4 5 6];
eo=2;
RM=0;
for i=1:1:6
    D(i)=a*(e(i)-eo)^b;
    E(i)=e(i)*(1-D(i));
    R(i)=(K(i)-E(i))^2;
    RM=RM+R(i);
end
RMS=(RM)^(1/2);
RMS=matlabFunction(RMS,'Vars',{[v(1),v(2)]});
v = [0.12 2];
c = fminsearch(RMS, v);
disp(c);
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