In an assignment A(I) = B, the number of elements in B and I must be the same.

What Is this error?

[Stelios Fanourakis]

clc;

N = 100;

w = 0.5;
q = 0.01;
r = 0.1;

%%This is the transition matrix
A = [cos(w)    sin(w)/w; 
     -w*sin(w) cos(w)];

%%This is the process noise covariance
Q = [0.5*q*(w-cos(w)*sin(w))/w^3 0.5*q*sin(w)^2/w^2;
     0.5*q*sin(w)^2/w^2          0.5*q*(w+cos(w)*sin(w))/w];

   % This is the true initial value
  x0 = [0;0.1]; 

X = zeros(2,N);  % The true signal
Y = zeros(1,N);  % Measurements
T = 1:N;         % Time
x = x0;

for i=1:N %kalman predict x(i) = A*x P(i) = A * P * A' + Q; end

Answer 1

[Image Analyst]

For example you're trying to stuff a whole 2-by-7 matrix into an element that can take only one number.

For another example

A = [2,3,4];
B = [3,4,5,6,7,8,9,1,2,3,4,5,6,7]
A(2) = B;  % Stuff 14 numbers into a space that only holds one.

So the number of elements and the shape of "I" is not the same as "B". If you can be more specific (like by showing your code), then we'll be able to also.