take descriptive comment all the way

2024-10-06 11:08:02 -04:00 · 2024-10-06 11:08:02 -04:00 · 94fda5dd5a
parent 310c4ffae9
commit 94fda5dd5a
1 changed files with 3 additions and 0 deletions
--- a/gtsam/hybrid/HybridGaussianFactorGraph.cpp
+++ b/gtsam/hybrid/HybridGaussianFactorGraph.cpp
@ -305,6 +305,9 @@ static std::shared_ptr<Factor> createDiscreteFactor(

    // Negative logspace version of:
    // exp(-factor->error(kEmpty)) / conditional->normalizationConstant();
+    // = exp(-factor->error(kEmpty)) * \sqrt{|2πΣ|};
+    // log = -(-factor->error(kEmpty) + log(\sqrt{|2πΣ|}))
+    // = factor->error(kEmpty) - log(\sqrt{|2πΣ|})
    // negLogConstant gives `-log(k)`
    // which is `-log(k) = log(1/k) = log(\sqrt{|2πΣ|})`.
    return factor->error(kEmpty) - conditional->negLogConstant();