I have

```
W = rand(12)
x = rand(12, 1000)
```

and I would like multi each column of `x`

by `W`

element-wise then take the maximum of the column. I should end up with a vector with the same size as the number of coumns of `x`

The best way I can think of is

`[maximum(x[:,j] .* W) for j in 1:size(x, 2)]`

but I think there should a more efficient way

Actual, I wanted to do this in Flux.jl so the code is more like

```
# start random parameters
x = rand(12, 1000)
W = param([1 for i=1:12])
x1 = [maximum(x[:,j] .* W) for j in 1:size(x, 2)]
```