How do I make my function take vectors as an input?

I was trying to make a function which finds the amount of iterations it will take for any given number to get to 1 in the collatz conjecture. I found that my code works for scalar inputs, but when I use a vector as an input it only gives me the output for the last element of the vector. Any help would be greatly appreciated.

       function [count]=updown(numbers)
for i=1:numel(numbers)
    count=0;
    x(i)=numbers(i);
while x>1
    if rem(x,2)==0
        x=x./2;
    else
        x=3*x+1;
    end
        count=count+1;
end
end
count
end

Answer 1

[Steven Lord]

You want an array of counts, one per element of the array that you pass in as input? Preallocate that array using the zeros and size functions then assign into and add to the appropriate element of that array while you're operating on each element of the input array.