We are not told what n is, but we can deduce from evidence that n = 2
syms theta phi
n = 2
Theta_n=(theta:(phi/n):(theta+phi));
size(Theta_n)
nNN=size(Theta_n,2)
and we see that nNN is n+1.
We do not know what m is, so let us say m = 1 for the moment. We do not know what R is
m = 1
syms R
x=zeros(n+1,1,'like',R);
y=zeros(n+1,1,'like',R);
for j=1:m+1
for i=((j-1)*nNN+1):j*nNN
[j,i]
x(i,1)=R*cos(Theta_n(1,i));
y(i,1)=R*sin(Theta_n(1,i));
end
end
Your code is effectively trying to access Theta_n as if it were a vector intended to represent an array with nNN = (n+1) {=3 here} rows, and m+1 columns. But that is a problem because you can be sure that Theta_n only has n+1 elements, so it cannot be used to emulate an array with more than one column. If your m is greater than 0, then j can be greater than 1, and you will have problems.
And really it is a waste to hae those loops. Just do
x = reshape(R * cos(Theta_n), nNN, []);
y = reshape(R * sin(Theta_n), nNN, []);
with no looping. You will still only end up with one column in x and y, but you will do so without an error message.
If you are relying upon there ending up with m+1 columns in x and y, then your definition of Theta_n would have to change, such as if you were adding multiples of phi.
