nautilus_analysis/python/statistics/tracking_error.rs
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4//
5// Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
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13// limitations under the License.
14// -------------------------------------------------------------------------------------------------
15
16use std::collections::BTreeMap;
17
18use pyo3::prelude::*;
19
20use super::transform_returns;
21use crate::{statistic::PortfolioStatistic, statistics::tracking_error::TrackingError};
22
23#[pymethods]
24#[pyo3_stub_gen::derive::gen_stub_pymethods]
25impl TrackingError {
26 /// Calculates the tracking error of portfolio returns relative to a benchmark.
27 ///
28 /// Tracking error is the volatility of the active return (portfolio minus benchmark):
29 ///
30 /// `TE = std(active) * sqrt(period)`
31 ///
32 /// where `active_i = portfolio_i - benchmark_i`, `std` uses Bessel's correction
33 /// (`ddof = 1`), and the result is annualized by the square root of the specified period
34 /// (default: 252 trading days).
35 ///
36 /// # References
37 ///
38 /// - Roll, R. (1992). "A Mean/Variance Analysis of Tracking Error".
39 /// *Journal of Portfolio Management*, 18(4), 13-22.
40 /// - CFA Institute Investment Foundations, 3rd Edition
41 #[new]
42 #[pyo3(signature = (period=None))]
43 fn py_new(period: Option<usize>) -> Self {
44 Self::new(period)
45 }
46
47 fn __repr__(&self) -> String {
48 self.to_string()
49 }
50
51 #[getter]
52 #[pyo3(name = "name")]
53 fn py_name(&self) -> String {
54 self.name()
55 }
56
57 #[pyo3(name = "calculate_from_returns")]
58 fn py_calculate_from_returns(&self, _returns: BTreeMap<u64, f64>) -> Option<f64> {
59 None
60 }
61
62 #[pyo3(name = "calculate_from_realized_pnls")]
63 fn py_calculate_from_realized_pnls(&self, _realized_pnls: Vec<f64>) -> Option<f64> {
64 None
65 }
66
67 #[pyo3(name = "calculate_from_positions")]
68 fn py_calculate_from_positions(&self, _positions: Vec<Py<PyAny>>) -> Option<f64> {
69 None
70 }
71
72 #[pyo3(name = "calculate_from_returns_with_benchmark")]
73 #[expect(clippy::needless_pass_by_value)]
74 fn py_calculate_from_returns_with_benchmark(
75 &self,
76 returns: BTreeMap<u64, f64>,
77 benchmark: BTreeMap<u64, f64>,
78 ) -> Option<f64> {
79 self.calculate_from_returns_with_benchmark(
80 &transform_returns(&returns),
81 &transform_returns(&benchmark),
82 )
83 }
84}