reductionml_core/metrics/
ips.rs

1use crate::{metrics::Metric, utils::AsInner, ActionProbsPrediction, CBLabel, Features};
2
3use super::MetricValue;
4
5pub struct IpsMetric {
6    pub examples_count: u64,
7    pub weighted_reward: f32,
8}
9
10impl IpsMetric {
11    pub fn new() -> IpsMetric {
12        IpsMetric {
13            examples_count: 0,
14            weighted_reward: 0.0,
15        }
16    }
17}
18
19impl Default for IpsMetric {
20    fn default() -> Self {
21        Self::new()
22    }
23}
24
25impl Metric for IpsMetric {
26    fn add_point(
27        &mut self,
28        _features: &Features,
29        label: &crate::types::Label,
30        prediction: &crate::types::Prediction,
31    ) {
32        let label: &CBLabel = label.as_inner().unwrap();
33        let pred: &ActionProbsPrediction = prediction.as_inner().unwrap();
34
35        let p_log = label.probability;
36        let p_pred = pred
37            .0
38            .iter()
39            .find(|(action, _)| action == &label.action)
40            .unwrap()
41            .1;
42
43        let w = p_pred / p_log;
44
45        self.weighted_reward += (-1.0 * label.cost) * w;
46        self.examples_count += 1;
47    }
48
49    fn get_value(&self) -> MetricValue {
50        MetricValue::Float(self.weighted_reward / (self.examples_count as f32))
51    }
52
53    fn get_name(&self) -> String {
54        "Estimated reward (IPS)".to_owned()
55    }
56}
reductionml_core/metrics/ips.rs

reductionml_core/metrics/
ips.rs
