pub fn diffinv<T: Num + Add + AddAssign + Copy + From<u8>>(
x: &[T],
d: usize
) -> Vec<T>
Expand description
Calculate the inverse difference of a vector.
Arguments
&x
- Reference to input vector slice of length n.d
- How often the inverse differences should be applied.
Returns
- Output vector of length n+d containing the inversed values. The first d values are zero.
Example
use arima::util;
let x = [1, 1, 1, 1, 1];
let y = util::diffinv(&x, 1);
assert_eq!(y, &[0, 1, 2, 3, 4, 5]);
let z = util::diff(&y, 1);
assert_eq!(z, x);