Assuming I have a Numpy n x 2 array `y`

: `array([[1, 1], [2, 3], [1, 4], ...])`

and a Numpy n x 1 array `x`

: `array([2, 4, 5, ...])`

, how can I efficiently obtain the following result, n x 2 array: `array([2, 2], [8, 12], [5, 20], ...])`

, where each element (array) of the `y`

is multiplied by corresponding value from array `x`

?

I can do it via a cycle but looking for more performant approaches.

### >Solution :

With an actual n-by-1 `x`

, you could just do `x * y`

. Your `x`

is 1-dimensional, n-not-by-anything, so you’d have to reshape it first:

```
x.reshape((n, 1)) * y
```