From d4d6012712da78cf8c9b13e348c22c8ed36dc8f1 Mon Sep 17 00:00:00 2001
From: Thomas Colthurst <thomaswc@google.com>
Date: Mon, 8 Jul 2024 19:38:22 +0000
Subject: [PATCH] Fix categorical logp to be conditional probability

---
 cxx/emissions/categorical.hh      | 10 +---------
 cxx/emissions/categorical_test.cc |  2 +-
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/cxx/emissions/categorical.hh b/cxx/emissions/categorical.hh
index 40bf4ec..477bf1a 100644
--- a/cxx/emissions/categorical.hh
+++ b/cxx/emissions/categorical.hh
@@ -31,15 +31,7 @@ class CategoricalEmission : public Emission<int> {
   }
 
   double logp(const std::pair<int, int>& x) const {
-    double lp;
-    for (size_t i = 0; i < emission_dists.size(); ++i) {
-      if (std::cmp_equal(i, x.first)) {
-        lp += emission_dists[i].logp(x.second);
-      } else {
-        lp += emission_dists[i].logp_score();
-      }
-    }
-    return lp;
+    return emission_dists[x.first].logp(x.second);
   }
 
   double logp_score() const {
diff --git a/cxx/emissions/categorical_test.cc b/cxx/emissions/categorical_test.cc
index faa8074..5015f04 100644
--- a/cxx/emissions/categorical_test.cc
+++ b/cxx/emissions/categorical_test.cc
@@ -22,7 +22,7 @@ BOOST_AUTO_TEST_CASE(test_simple) {
   ce.incorporate(std::make_pair<int, int>(4, 4));
   BOOST_TEST(ce.N == 2);
 
-  BOOST_TEST(ce.logp(std::make_pair<int, int>(2, 2)) == -4.8283137373023006,
+  BOOST_TEST(ce.logp(std::make_pair<int, int>(2, 2)) == -1.6094379124341003,
              tt::tolerance(1e-6));
 
   std::mt19937 prng;