making a rotation matrix

 {
clc
b = [cos((angle/180)*pi) -sin((angle/180)*pi);sin((angle/180)*pi) cos((angle/180)*pi)];
for i = 1:1:size(nr_out,1)
a = [nr_out(i,1);nr_out(i,2)];
c = b*a;
rotatie(i) = [c(1,1) c(2,1)];   
end
}

Hello I am trying to make a rotation matrix. To do that i multiply the x and y from a file with the rotation matrix [cos(a) -sin(a); sin(a) cos(a)] What I want is that the matrix 'rotatie' grows with in the first column the x value ( c(1,1)) and in the second column the y-value(c(2,1)).

The error it gives is this: In an assignment A(I) = B, the number of elements in B and I must be the same.

Gr jeroen

Answer 1

[Honglei Chen]

You need to do something like

rotatie(i,:) = [c(1,1) c(2,1)];

But if I understand your question correctly, you can do it without a loop

rotatie = (b*nr_out.').'

[Jeroen]

I am sorry I forgot to tell that the matrix nr_out is a matrix that consist of x,y,z,ex,ey,ez and I have to rotate the whole matrix with 20.58 degree in the xy-plane with their energies.

[Honglei Chen]

Then you can just use the first solution, use rotatie(i,:) instead of rotatie(i)