Create an array with repeating numbers

Question

Let's say I have this array:

1 2 3 4

and I want to create an array like this:

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

How could I create that?

Answer 1

From the documentation for repelem:

repelem Replicate elements of an array. U = repelem(V,N), where V is a vector, returns a vector of repeated elements of V.

So what you want is:

>> repelem([1 2 3 4],4)