In Matlab, the preferred way of doing this is: find(s < x)
In Julia, it's almost exactly the same: find(s .< x) If you don't need the indices, only the elements, you would do: s[s .< x] which, again, is almost identical to Matlab. The reason you are getting a matrix output is that [1 2 5 7 3 3] is actually a matrix (with one row) in Julia, which you then multiply with a (column) vector. If you want a vector, write [1, 2, 5, 7, 3, 3]