How to make a 3x3 matrix

Hello every one; I want to make a 3x3 general matrix using three different function as shown in code. It is working but I want to know how to save the results in three different lines of same matrix. Also how to run this matrix in command window for some defined value of theta. Thanks

syms theta;
for x=1:3

      beta=0:2*pi/3:4*pi/3;
      if x==1
      L1 =cos(theta+beta);

      elseif x==2
       L2=cos(theta+beta-2*pi/3); 

      else
       L3=cos(theta+beta+2*pi/3);  
      end

end

Answer 1

[Jan]

syms theta;
beta = 0:2*pi/3:4*pi/3;
L = [cos(theta+beta); ...
     cos(theta+beta-2*pi/3); ...
     cos(theta+beta+2*pi/3)]

Or if you really nee a loop:

syms theta;
beta = 0:2*pi/3:4*pi/3;
for x = 1:3
  if x==1
    L(1, :) = cos(theta+beta);
  elseif x==2
    L(2, :) = cos(theta+beta-2*pi/3); 
  else
    L(3, :) = cos(theta+beta+2*pi/3);  
  end
end

If your array is larger, care for a pre-allocation. A cheap method would be:

for x = 3:-1:1   % Backwards for implicit pre-allocation

[BILAL ASAD]

Thanks a lot