From 3c6bbf28d7022771dfe0e4b121da3810688e9a9c Mon Sep 17 00:00:00 2001
From: "Dr. Kashif Rasul" <kashif.rasul@gmail.com>
Date: Mon, 6 Apr 2020 11:38:35 +0200
Subject: [PATCH] scale alpha so that the var stays the same

---
 pts/modules/distribution_output.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pts/modules/distribution_output.py b/pts/modules/distribution_output.py
index ad08783..f1c9582 100644
--- a/pts/modules/distribution_output.py
+++ b/pts/modules/distribution_output.py
@@ -136,8 +136,8 @@ class NegativeBinomialOutput(DistributionOutput):
         mu, alpha = distr_args
 
         if scale is not None:
-            mu *= scale
-            alpha /= scale
+            alpha = (1 - scale + mu*alpha)/(mu*scale*scale)
+            mu = mu*scale
 
         n = 1.0 / alpha
         p = mu * alpha / (1.0 + mu * alpha)