rust_finprim/rate/
cagr.rs

1use crate::FloatLike;
2
3/// CAGR - Compound Annual Growth Rate
4///
5/// The compound annual growth rate (CAGR) is the rate of return that would be required for an investment
6/// to grow from its beginning balance to its ending balance, assuming the profits were reinvested at the
7/// end of each period of the investment’s life span.
8///
9/// # Arguments
10/// * `beginning_balance` - The initial investment or balance
11/// * `ending_balance` - The final investment or balance
12/// * `n` - The number of years
13///
14/// # Returns
15/// * The compound annual growth rate (CAGR)
16///
17/// # Example
18/// * Beginning balance of $1000, ending balance of $2000 after 5 years
19/// ```
20/// use rust_finprim::rate::cagr;
21///
22/// let beginning_balance = 1000.0;
23/// let ending_balance = 2000.0;
24/// let n = 5.0;
25///
26/// cagr(beginning_balance, ending_balance, n);
27/// ```
28pub fn cagr<T: FloatLike>(beginning_balance: T, ending_balance: T, n: T) -> T {
29    (ending_balance / beginning_balance).powf(T::one() / n) - T::one()
30}
31
32#[cfg(test)]
33mod tests {
34    use super::*;
35
36    #[cfg(not(feature = "std"))]
37    extern crate std;
38    #[cfg(not(feature = "std"))]
39    use std::assert;
40
41    #[test]
42    fn test_cagr() {
43        let beginning_balance = 1000.0;
44        let ending_balance = 500.0;
45        let n = 5.0;
46        let result = cagr(beginning_balance, ending_balance, n);
47        let expected: f64 = -0.12945;
48        assert!(
49            (result - expected).abs() < 1e-5,
50            "Failed on case: {}. Expected: {}, Result: {}",
51            "Beginning balance of $1000, ending balance of $500 after 5 years",
52            expected,
53            result
54        );
55    }
56}
rust_finprim/rate/cagr.rs

rust_finprim/rate/
cagr.rs
