light_curve_feature/features/
minimum_time_interval.rs

1use crate::evaluator::*;
2use itertools::Itertools;
3
4macro_const! {
5    const DOC: &str = r"
6Minimum time interval between consequent observations
7
8$$
9\min{(t_{i+1} - t_i)}
10$$
11
12Note: highly cadence-dependent feature.
13
14- Depends on: **time**
15- Minimum number of observations: **2**
16- Number of features: **1**
17";
18}
19
20#[doc = DOC!()]
21#[derive(Clone, Default, Debug, Deserialize, Serialize, JsonSchema)]
22pub struct MinimumTimeInterval {}
23
24impl MinimumTimeInterval {
25    pub fn new() -> Self {
26        Self {}
27    }
28
29    pub const fn doc() -> &'static str {
30        DOC
31    }
32}
33
34lazy_info!(
35    MINIMUM_TIME_INTERVAL_INFO,
36    MinimumTimeInterval,
37    size: 1,
38    min_ts_length: 2,
39    t_required: true,
40    m_required: false,
41    w_required: false,
42    sorting_required: true,
43);
44
45impl FeatureNamesDescriptionsTrait for MinimumTimeInterval {
46    fn get_names(&self) -> Vec<&str> {
47        vec!["minimum_time_interval"]
48    }
49
50    fn get_descriptions(&self) -> Vec<&str> {
51        vec!["minimum time interval between consequent observations"]
52    }
53}
54
55impl<T> FeatureEvaluator<T> for MinimumTimeInterval
56where
57    T: Float,
58{
59    fn eval(&self, ts: &mut TimeSeries<T>) -> Result<Vec<T>, EvaluatorError> {
60        self.check_ts_length(ts)?;
61        let dt =
62            ts.t.as_slice()
63                .iter()
64                .tuple_windows()
65                .map(|(&a, &b)| b - a)
66                .min_by(|a, b| a.partial_cmp(b).unwrap())
67                .unwrap();
68        Ok(vec![dt])
69    }
70}
71
72#[cfg(test)]
73#[allow(clippy::unreadable_literal)]
74#[allow(clippy::excessive_precision)]
75mod tests {
76    use super::*;
77    use crate::tests::*;
78
79    check_feature!(MinimumTimeInterval);
80
81    feature_test!(
82        minimum_time_interval,
83        [MinimumTimeInterval::new()],
84        [0.1],
85        [0.0_f32, 0.5, 0.6, 1.6, 10.6],
86    );
87}