From 7167d55bccee9a84ec7c6cd9c47a7e4a7dcf8f67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=90=D1=80=D1=82=D1=91=D0=BC=20=D0=9F=D0=B0=D0=B2=D0=BB?=
 =?UTF-8?q?=D0=BE=D0=B2=20=5BArtyom=20Pavlov=5D?= <newpavlov@gmail.com>
Date: Wed, 8 May 2024 18:43:52 +0300
Subject: [PATCH] Tweak beta computation in the Gamma distribution

---
 rand_distr/src/gamma.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/rand_distr/src/gamma.rs b/rand_distr/src/gamma.rs
index 11385beac1..fbafd26824 100644
--- a/rand_distr/src/gamma.rs
+++ b/rand_distr/src/gamma.rs
@@ -620,8 +620,12 @@ where
         if a > F::one() {
             // Algorithm BB
             let alpha = a + b;
-            let beta =
-                ((alpha - F::from(2.).unwrap()) / (F::from(2.).unwrap() * a * b - alpha)).sqrt();
+
+            let two = F::from(2.).unwrap();
+            let beta_numer = alpha - two;
+            let beta_denom = two * a * b - alpha;
+            let beta = (beta_numer / beta_denom).sqrt();
+
             let gamma = a + F::one() / beta;
 
             Ok(Beta {