MATLAB: How do i reshape this matrix

Question

Hello all, I'm looking for some help on the job below where I am simply trying to reshape a matrix. The data im working with is real, but i have used syms below to hopefully make it a bit easier to read.

syms a11 b11 c11 a12 b12 c12 a21 b21 c21 a22 b22 c22 a13 b13 c13 a23 b23 c23
X=[a11 b11 c11 a12 b12 c12 a13 b13 c13; 
   a21 b21 c21 a22 b22 c22 a23 b23 c23]
% Dimensions of new matrix M
rows=size(X,1)*size(X,2)/3
cols=3
% ----------- My attempt
for i=1:rows
    for j=1:size(X,1)
        for k=1:3:(size(X,2))
                M(i,1:cols)=X(j,k:(k+2))
        end
    end
end

The result from my attempt is not what im after at all!

M =
[ a23, b23, c23]
[ a23, b23, c23]
[ a23, b23, c23]
[ a23, b23, c23]
[ a23, b23, c23]
[ a23, b23, c23]

How do I get the code to position each set of three elements (a,b,c) from X sequentially in matrix M like below?

M=[a11 b11 c11;
   a12 b12 c12;
   a13 b13 c13;
   a21 b21 c21;
   a22 b22 c22;
   a23 b23 c23]

Answer 1

I'll do it with a numeric matrix. I've replaced a,b and c with a leading 1,2 and 3.

X=[111 211 311 112 212 312 113 213 313
    121 221 321 122 222 322 123 223 323];
M=reshape(X',[3,6])'
M = 6×3
   111   211   311
   112   212   312
   113   213   313
   121   221   321
   122   222   322
   123   223   323
●