how to combine matrixes

I have to combine two matrices for example

a=[10 20 30 40 50 60]

   b=[11 22 33 44 55 66]

based on some random seed for example r =2 ,combine 2 values from the matrix a and b to form a output matrix

c=[10 20 11 22 30 40 33 44 50 60 55 66]

Please help me

Answer 1

[Azzi Abdelmalek]

   a=[10 20 30 40 50 60]
   b=[11 22 33 44 55 66]
   r=2
   out=[reshape(a,r,[]);reshape(b,r,[])]
   out=out(:)'

[Sharen H]

Thanks

Answer 2

[Azzi Abdelmalek]

General case

   a=[10 20 30 40 50 60];
   b=[11 22 33 44 55 66];
   r=randi(numel(a));
   id=r-mod(numel(a),r);
   if id~=r
       a(end+1:end+id)=nan;
       b(end+1:end+id)=nan;
   end
   out=[reshape(a,r,[]);reshape(b,r,[])];
   out=out(:)';
   out(isnan(out))=[]

[Sharen H]

this code gives an error called Undefined function or method 'randi' for input arguments of type 'double' what does it mean

[Azzi Abdelmalek]

Your version of Matlab does not support rndi, then instead of r=randi(numel(a)); use

[~ ,r]=max(rand(1,numel(a)))