Suppose I have a list of numbers

```
L = [16, 5, 14, 7, 21, 9, 14, 19, 27, 1, 18, 5,27, 15, 14, 5, 27, 20, 15, 27, 15, 14, 5]

```

I want to convert `L` into 3x1 vectors until the whole L is used. We use 27 if not enough entries are there. And then we augment the vector to form a matrix.

How can I do that? Can someone please give a hint?

[![enter image description here](https://i.stack.imgur.com/TpNsn.png)](https://i.stack.imgur.com/TpNsn.png)