nautilus_indicators/momentum/
stochastics.rsuse std::{
collections::VecDeque,
fmt::{Debug, Display},
};
use nautilus_model::data::Bar;
use crate::indicator::Indicator;
#[repr(C)]
#[derive(Debug)]
#[cfg_attr(
feature = "python",
pyo3::pyclass(module = "nautilus_trader.core.nautilus_pyo3.indicators")
)]
pub struct Stochastics {
pub period_k: usize,
pub period_d: usize,
pub value_k: f64,
pub value_d: f64,
pub initialized: bool,
has_inputs: bool,
highs: VecDeque<f64>,
lows: VecDeque<f64>,
c_sub_1: VecDeque<f64>,
h_sub_l: VecDeque<f64>,
}
impl Display for Stochastics {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}({},{})", self.name(), self.period_k, self.period_d,)
}
}
impl Indicator for Stochastics {
fn name(&self) -> String {
stringify!(Stochastics).to_string()
}
fn has_inputs(&self) -> bool {
self.has_inputs
}
fn initialized(&self) -> bool {
self.initialized
}
fn handle_bar(&mut self, bar: &Bar) {
self.update_raw((&bar.high).into(), (&bar.low).into(), (&bar.close).into());
}
fn reset(&mut self) {
self.highs.clear();
self.lows.clear();
self.c_sub_1.clear();
self.h_sub_l.clear();
self.value_k = 0.0;
self.value_d = 0.0;
self.has_inputs = false;
self.initialized = false;
}
}
impl Stochastics {
#[must_use]
pub fn new(period_k: usize, period_d: usize) -> Self {
Self {
period_k,
period_d,
has_inputs: false,
initialized: false,
value_k: 0.0,
value_d: 0.0,
highs: VecDeque::with_capacity(period_k),
lows: VecDeque::with_capacity(period_k),
h_sub_l: VecDeque::with_capacity(period_d),
c_sub_1: VecDeque::with_capacity(period_d),
}
}
pub fn update_raw(&mut self, high: f64, low: f64, close: f64) {
if !self.has_inputs {
self.has_inputs = true;
}
self.highs.push_back(high);
self.lows.push_back(low);
if !self.initialized
&& self.highs.len() == self.period_k
&& self.lows.len() == self.period_k
{
self.initialized = true;
}
let k_max_high = self.highs.iter().copied().fold(f64::NEG_INFINITY, f64::max);
let k_min_low = self.lows.iter().copied().fold(f64::INFINITY, f64::min);
self.c_sub_1.push_back(close - k_min_low);
self.h_sub_l.push_back(k_max_high - k_min_low);
if k_max_high == k_min_low {
return;
}
self.value_k = 100.0 * ((close - k_min_low) / (k_max_high - k_min_low));
self.value_d =
100.0 * (self.c_sub_1.iter().sum::<f64>() / self.h_sub_l.iter().sum::<f64>());
}
}
#[cfg(test)]
mod tests {
use nautilus_model::data::Bar;
use rstest::rstest;
use crate::{
indicator::Indicator,
momentum::stochastics::Stochastics,
stubs::{bar_ethusdt_binance_minute_bid, stochastics_10},
};
#[rstest]
fn test_stochastics_initialized(stochastics_10: Stochastics) {
let display_str = format!("{stochastics_10}");
assert_eq!(display_str, "Stochastics(10,10)");
assert_eq!(stochastics_10.period_d, 10);
assert_eq!(stochastics_10.period_k, 10);
assert!(!stochastics_10.initialized);
assert!(!stochastics_10.has_inputs);
}
#[rstest]
fn test_value_with_one_input(mut stochastics_10: Stochastics) {
stochastics_10.update_raw(1.0, 1.0, 1.0);
assert_eq!(stochastics_10.value_d, 0.0);
assert_eq!(stochastics_10.value_k, 0.0);
}
#[rstest]
fn test_value_with_three_inputs(mut stochastics_10: Stochastics) {
stochastics_10.update_raw(1.0, 1.0, 1.0);
stochastics_10.update_raw(2.0, 2.0, 2.0);
stochastics_10.update_raw(3.0, 3.0, 3.0);
assert_eq!(stochastics_10.value_d, 100.0);
assert_eq!(stochastics_10.value_k, 100.0);
}
#[rstest]
fn test_value_with_ten_inputs(mut stochastics_10: Stochastics) {
let high_values = [
1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0,
];
let low_values = [
0.9, 1.9, 2.9, 3.9, 4.9, 5.9, 6.9, 7.9, 8.9, 9.9, 10.1, 10.2, 10.3, 11.1, 11.4,
];
let close_values = [
1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0,
];
for i in 0..15 {
stochastics_10.update_raw(high_values[i], low_values[i], close_values[i]);
}
assert!(stochastics_10.initialized());
assert_eq!(stochastics_10.value_d, 100.0);
assert_eq!(stochastics_10.value_k, 100.0);
}
#[rstest]
fn test_initialized_with_required_input(mut stochastics_10: Stochastics) {
for i in 1..10 {
stochastics_10.update_raw(f64::from(i), f64::from(i), f64::from(i));
}
assert!(!stochastics_10.initialized);
stochastics_10.update_raw(10.0, 12.0, 14.0);
assert!(stochastics_10.initialized);
}
#[rstest]
fn test_handle_bar(mut stochastics_10: Stochastics, bar_ethusdt_binance_minute_bid: Bar) {
stochastics_10.handle_bar(&bar_ethusdt_binance_minute_bid);
assert_eq!(stochastics_10.value_d, 49.090_909_090_909_09);
assert_eq!(stochastics_10.value_k, 49.090_909_090_909_09);
assert!(stochastics_10.has_inputs);
assert!(!stochastics_10.initialized);
}
#[rstest]
fn test_reset(mut stochastics_10: Stochastics) {
stochastics_10.update_raw(1.0, 1.0, 1.0);
assert_eq!(stochastics_10.c_sub_1.len(), 1);
assert_eq!(stochastics_10.h_sub_l.len(), 1);
stochastics_10.reset();
assert_eq!(stochastics_10.value_d, 0.0);
assert_eq!(stochastics_10.value_k, 0.0);
assert_eq!(stochastics_10.h_sub_l.len(), 0);
assert_eq!(stochastics_10.c_sub_1.len(), 0);
assert!(!stochastics_10.has_inputs);
assert!(!stochastics_10.initialized);
}
}