MATLAB: Matrix element changing with loop

Question

I keep getting Dimensions of matrices being concatenated are not consistent error.

for k=1:61

a(:,k)=angle(k,:);

A=[cosd(5) -sind(a); -sind(5) cosd(a)];

x=A\B;

end

I don't get what I am doing wrong

Answer 1

5 is a scalar. A scalar has size 1x1.

On the second loop iteration a has size Nx2 (we don't know the actual size because you did explain what size angle is).

Then you calculate some trig functions using those 5 and a, giving 1x1 and Nx2 arrays. You then try to concatenate those arrays like this:

[1x1,Nx2;1x1,Nx2]

which is an error if N>1 because then the number of rows are different, which means that those arrays cannot be concatenated together horizontally:

• To horizontally concatenate arrays they must have the same number of rows.
• To vertically concatenate arrays they must have the same number of columns.

Check the sizes of the arrays that you are trying to concatenate and you will find that one/both of those conditions are not fulfilled.