From 82f36d908b61ca5ae1192485f81c1d59c88a25b9 Mon Sep 17 00:00:00 2001
From: Dominic Steinitz <dominic@steinitz.org>
Date: Wed, 11 Jan 2023 10:55:12 +0000
Subject: [PATCH] Re-introduce normalize

---
 src/Control/Monad/Bayes/Population.hs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/Control/Monad/Bayes/Population.hs b/src/Control/Monad/Bayes/Population.hs
index be670df2..51c47833 100644
--- a/src/Control/Monad/Bayes/Population.hs
+++ b/src/Control/Monad/Bayes/Population.hs
@@ -22,6 +22,7 @@ module Control.Monad.Bayes.Population
     fromWeightedList,
     spawn,
     multinomial,
+    normalize,
     resampleMultinomial,
     systematic,
     resampleSystematic,
@@ -50,6 +51,7 @@ import Control.Monad.Bayes.Weighted
   ( Weighted,
     applyWeight,
     extractWeight,
+    unweighted,
     weighted,
     withWeight,
   )
@@ -274,3 +276,7 @@ hoist ::
   Population m a ->
   Population n a
 hoist f = fromWeightedList . f . population
+
+-- | Normalizes the weights in the population so that their sum is 1.
+normalize :: (Monad m) => Population m a -> Population m a
+normalize = hoist unweighted . extractEvidence