Crate light_curve_feature[−][src]

Expand description

light-curve-feature is a part of light-curve family that implements extraction of numerous light curve features used in astrophysics.

All features are available in Feature enum, and the recommended way to extract multiple features at once is FeatureExtractor struct built from a Vec<Feature>. Data is represented by TimeSeries struct built from time, magnitude (or flux) and weights arrays, all having the same length. Note that multiple features interpret weight array as inversed squared observation errors.

use light_curve_feature::*;

// Let's find amplitude and reduced Chi-squared of the light curve
let fe = FeatureExtractor::<_, Feature<_>>::new(vec![Amplitude::default().into(), ReducedChi2::default().into()]);
// Define light curve
let time = [0.0, 1.0, 2.0, 3.0, 4.0];
let magn = [-1.0, 2.0, 1.0, 3.0, 4.5];
let weights = [5.0, 10.0, 2.0, 10.0, 5.0]; // inverse squared magnitude errors
let mut ts = TimeSeries::new(&time, &magn, &weights);
// Get results and print
let result = fe.eval(&mut ts)?;
let names = fe.get_names();
println!("{:?}", names.iter().zip(result.iter()).collect::<Vec<_>>());

There are a couple of meta-features, which transform a light curve before feature extraction. For example Bins feature accumulates data inside time-windows and extracts features from this new light curve.

use light_curve_feature::*;
use ndarray::Array1;

// Define features, "raw" MaximumSlope and binned with zero offset and 1-day window
let max_slope: Feature<_> = MaximumSlope::default().into();
let bins: Feature<_> = {
    let mut bins = Bins::new(1.0, 0.0);
    bins.add_feature(max_slope.clone());
    bins.into()
};
let fe = FeatureExtractor::<_, Feature<_>>::new(vec![max_slope, bins]);
// Define light curve
let time = [0.1, 0.2, 1.1, 2.1, 2.1];
let magn = [10.0, 10.1, 10.5, 11.0, 10.9];
// We don't need weight for MaximumSlope, this would assign unity weight
let mut ts = TimeSeries::new_without_weight(&time, &magn);
// Get results and print
let result = fe.eval(&mut ts)?;
println!("{:?}", result);