How to genneral a repeat array

I have a array a = [1, 2 , 3 ,4], I want to repeat every element 3 times. The result is [1,1,1,2,2,2,3,3,3,4,4,4]

Answer 1

[Binbin Qi]

You can use repelem function to accomplish your question

a =

       1     2     3     4

>> repelem(a, 3)

ans =

       1     1     1     2     2     2     3     3     3     4     4     4

Answer 2

[KSSV]

   k = [1, 2 , 3 ,4] ;
   l = repelem(k,3)

Answer 3

[Andrei Bobrov]

For users MATLAB R2014b and older

out = reshape(repmat(a(:)',3,1),[],1)';

or

out = kron(a,ones(1,3));