From c7c532b2195bfb5992d1b3bc776115d87e75ce4a Mon Sep 17 00:00:00 2001
From: Robbie McKinstry <thesnowmancometh@gmail.com>
Date: Fri, 29 Nov 2024 18:42:49 -0500
Subject: [PATCH] Attempt to catch error where NaN is introduced.

---
 src/stats/chi.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/stats/chi.rs b/src/stats/chi.rs
index b867050..592c3a2 100644
--- a/src/stats/chi.rs
+++ b/src/stats/chi.rs
@@ -25,7 +25,8 @@ fn test_statistic<const N: usize, C: Categorical<N>>(table: &ContingencyTable<N,
         let observed_count = table.observed_by_index(i) as i64;
         let diff = observed_count - expected_count;
         let error = diff.pow(2) as f64;
-        let incremental_error = error / (expected_count as f64);
+        let incremental_error = error / (expected_count as f64).min(1.0);
+        debug_assert!(!incremental_error.is_nan(), "The error must never be NaN.");
         sum += incremental_error;
     }
     sum