fn reshape(&self, (r, c): (usize, usize), shape: Shape) -> Matrix {
        assert_eq!(self.len(), r * c);
        let mut m = zeros_shape(r, c, shape);
        m.data = self[..].to_vec();
        m
    }
Vector to Matrix

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

fn main() {
let a = c!(1,2,3,4,5,6);
let b1 = a.reshape((3,2), Row);
let b2 = a.reshape((3,2), Col);
assert_eq!(b1, ml_matrix("1 2;3 4;5 6"));
assert_eq!(b2, ml_matrix("1 4;2 5;3 6"));
}
```
src/traits/sugar.rs