fn add_col(&self, v: &Self::Vec) -> Matrix {
        assert_eq!(self.len(), v.len());
        let mut x = self[..].to_vec();
        x.extend_from_slice(&v[..]);
        x.reshape((self.len(), 2), Shape::Col)
    }
Vector + Vector = Matrix

```
#[macro_use]
extern crate peroxide;
use peroxide::fuga::*;

fn main() {
let a = c!(1,2,3);
let b = c!(4,5,6);
let c1 = a.add_row(&b);
let c2 = a.add_col(&b);
assert_eq!(c1, ml_matrix("1 2 3;4 5 6"));
assert_eq!(c2, ml_matrix("1 4;2 5;3 6"));
}
```
src/traits/sugar.rs