From ee78b8e298f4cc42d7f0a6191aeb5e0dba9dee03 Mon Sep 17 00:00:00 2001
From: Adil Zouitine <adilzouitinegm@gmail.com>
Date: Sat, 21 Oct 2023 18:09:58 +0200
Subject: [PATCH] Add max score normalisation

---
 src/anomaly/half_space_tree.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/anomaly/half_space_tree.rs b/src/anomaly/half_space_tree.rs
index 2701fed..bbdae3b 100644
--- a/src/anomaly/half_space_tree.rs
+++ b/src/anomaly/half_space_tree.rs
@@ -192,6 +192,7 @@ impl<F: Float + FromPrimitive + AddAssign + SubAssign + MulAssign + DivAssign> H
             }
         }
         if do_score {
+            score = F::one() - (score / self.max_score());
             return Some(score);
         }
         return None;
@@ -202,4 +203,9 @@ impl<F: Float + FromPrimitive + AddAssign + SubAssign + MulAssign + DivAssign> H
     pub fn score_one(&mut self, observation: &Observation<F>) -> Option<F> {
         self.update(observation, true, false)
     }
+    fn max_score(&self) -> F {
+        F::from(self.n_trees).unwrap()
+            * F::from(self.window_size).unwrap()
+            * (F::from(2.).unwrap().powi(self.height as i32 + 1) - F::one())
+    }
 }