MATLAB: Expanding a Matrix with Repmat/Reshape

Question

I have two vectors:

x = [3 6 7 10]
y = [2 2 2 4]

I am trying to create vector

z = [3 3 6 6 7 7 10 10 10 10]

So each element x(i) is repeated y(i) times. This is straight forward with a for loop, but I'm trying to avoid looping, if possible. The size and values of x and y may change as well (they are populated by variables).

Here's the loop version:

    z= [];
    for i = 1:numel(y)
        z= [z, repmat(x(i), 1, y(i))];
    end

Any help is appreciated.

Answer 1

E.g.,

z = cell2mat(cellfun(@(x,y)repmat(x,1,y),num2cell(x),num2cell(y),'Uni',false));

But this just hides the loops in the background.