Function x_centre 

pub fn x_centre(dim: &Dimension, extent: &Extent) -> Vec<f64>

X-coordinates of cell centres for each column.

Returns a vector of length dim[0].

Example

use vaster::x_centre;

let xs = x_centre(&[4, 2], &[0.0, 4.0, 0.0, 2.0]);
assert_eq!(xs.len(), 4);
assert!((xs[0] - 0.5).abs() < 1e-10);
assert!((xs[3] - 3.5).abs() < 1e-10);