use crate::evaluator::*;
macro_const! {
const DOC: &str = r#"
Standard deviation to mean ratio
$$
\frac{\sigma_m}{\langle m \rangle}
$$
- Depends on: **magnitude**
- Minimum number of observations: **2**
- Number of features: **1**
"#;
}
#[doc = DOC!()]
#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
pub struct MeanVariance {}
lazy_info!(
MEAN_VARIANCE_INFO,
MeanVariance,
size: 1,
min_ts_length: 2,
t_required: false,
m_required: true,
w_required: false,
sorting_required: false,
);
impl MeanVariance {
pub fn new() -> Self {
Self {}
}
pub fn doc() -> &'static str {
DOC
}
}
impl FeatureNamesDescriptionsTrait for MeanVariance {
fn get_names(&self) -> Vec<&str> {
vec!["mean_variance"]
}
fn get_descriptions(&self) -> Vec<&str> {
vec!["standard deviation of magnitude to its mean value ratio"]
}
}
impl<T> FeatureEvaluator<T> for MeanVariance
where
T: Float,
{
fn eval(&self, ts: &mut TimeSeries<T>) -> Result<Vec<T>, EvaluatorError> {
self.check_ts_length(ts)?;
Ok(vec![ts.m.get_std() / ts.m.get_mean()])
}
}
#[cfg(test)]
#[allow(clippy::unreadable_literal)]
#[allow(clippy::excessive_precision)]
mod tests {
use super::*;
use crate::tests::*;
check_feature!(MeanVariance);
feature_test!(
mean,
[MeanVariance::new()],
[2.2832017440606585],
[1.0_f32, 1.0, 1.0, 1.0, 5.0, 6.0, 6.0, 6.0, 99.0],
);
}