Add parent hyperparameter to TAN & SPODE

CHANGELOG.md

@@ -10,6 +10,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Add a new hyperparameter to the BoostAODE class, *alphablock*, to control the way α is computed, with the last model or with the ensmble built so far. Default value is *false*.
+- Add a new hyperparameter to the SPODE class, *parent*, to set the root node of the model. If not value is set the root parameter of the constructor is used.
+- Add a new hyperparameter to the TAN class, *parent*, to set the root node of the model. If not set the first feature is used as root.
 
 ## [1.0.6] 2024-11-23
 

bayesnet/classifiers/SPODE.cc

@@ -8,14 +8,29 @@
 
 namespace bayesnet {
 
-    SPODE::SPODE(int root) : Classifier(Network()), root(root) {}
+    SPODE::SPODE(int root) : Classifier(Network()), root(root)
+    {
+        validHyperparameters = { "parent" };
+    }
 
+    void SPODE::setHyperparameters(const nlohmann::json& hyperparameters_)
+    {
+        auto hyperparameters = hyperparameters_;
+        if (hyperparameters.contains("parent")) {
+            root = hyperparameters["parent"];
+            hyperparameters.erase("parent");
+        }
+        Classifier::setHyperparameters(hyperparameters);
+    }
     void SPODE::buildModel(const torch::Tensor& weights)
     {
         // 0. Add all nodes to the model
         addNodes();
         // 1. Add edges from the class node to all other nodes
         // 2. Add edges from the root node to all other nodes
+        if (root >= static_cast<int>(features.size())) {
+            throw std::invalid_argument("The parent node is not in the dataset");
+        }
         for (int i = 0; i < static_cast<int>(features.size()); ++i) {
             model.addEdge(className, features[i]);
             if (i != root) {

bayesnet/classifiers/SPODE.h

@@ -10,14 +10,15 @@
 
 namespace bayesnet {
     class SPODE : public Classifier {
-    private:
-        int root;
-    protected:
-        void buildModel(const torch::Tensor& weights) override;
     public:
         explicit SPODE(int root);
         virtual ~SPODE() = default;
+        void setHyperparameters(const nlohmann::json& hyperparameters_) override;
         std::vector<std::string> graph(const std::string& name = "SPODE") const override;
+    protected:
+        void buildModel(const torch::Tensor& weights) override;
+    private:
+        int root;
     };
 }
 #endif

bayesnet/classifiers/TAN.cc

@@ -7,8 +7,20 @@
 #include "TAN.h"
 
 namespace bayesnet {
-    TAN::TAN() : Classifier(Network()) {}
+    TAN::TAN() : Classifier(Network())
+    {
+        validHyperparameters = { "parent" };
+    }
 
+    void TAN::setHyperparameters(const nlohmann::json& hyperparameters_)
+    {
+        auto hyperparameters = hyperparameters_;
+        if (hyperparameters.contains("parent")) {
+            parent = hyperparameters["parent"];
+            hyperparameters.erase("parent");
+        }
+        Classifier::setHyperparameters(hyperparameters);
+    }
     void TAN::buildModel(const torch::Tensor& weights)
     {
         // 0. Add all nodes to the model
@@ -23,7 +35,10 @@ namespace bayesnet {
             mi.push_back({ i, mi_value });
         }
         sort(mi.begin(), mi.end(), [](const auto& left, const auto& right) {return left.second < right.second;});
-        auto root = mi[mi.size() - 1].first;
+        auto root = parent == -1 ? mi[mi.size() - 1].first : parent;
+        if (root >= static_cast<int>(features.size())) {
+            throw std::invalid_argument("The parent node is not in the dataset");
+        }
         // 2. Compute mutual information between each feature and the class
         auto weights_matrix = metrics.conditionalEdge(weights);
         // 3. Compute the maximum spanning tree

bayesnet/classifiers/TAN.h

@@ -9,13 +9,15 @@
 #include "Classifier.h"
 namespace bayesnet {
     class TAN : public Classifier {
-    private:
-    protected:
-        void buildModel(const torch::Tensor& weights) override;
     public:
         TAN();
         virtual ~TAN() = default;
+        void setHyperparameters(const nlohmann::json& hyperparameters_) override;
         std::vector<std::string> graph(const std::string& name = "TAN") const override;
+    protected:
+        void buildModel(const torch::Tensor& weights) override;
+    private:
+        int parent = -1;
     };
 }
 #endif

tests/TestBayesModels.cc

@@ -267,4 +267,36 @@ TEST_CASE("Predict, predict_proba & score without fitting", "[Models]")
     REQUIRE_THROWS_WITH(clf.predict_proba(raw.Xt), message);
     REQUIRE_THROWS_WITH(clf.score(raw.Xv, raw.yv), message);
     REQUIRE_THROWS_WITH(clf.score(raw.Xt, raw.yt), message);
+}
+TEST_CASE("TAN & SPODE with hyperparameters", "[Models]")
+{
+    auto raw = RawDatasets("iris", true);
+    auto clf = bayesnet::TAN();
+    clf.setHyperparameters({
+        {"parent", 1},
+        });
+    clf.fit(raw.Xv, raw.yv, raw.features, raw.className, raw.states, raw.smoothing);
+    auto score = clf.score(raw.Xv, raw.yv);
+    REQUIRE(score == Catch::Approx(0.973333).epsilon(raw.epsilon));
+    auto clf2 = bayesnet::SPODE(0);
+    clf2.setHyperparameters({
+        {"parent", 1},
+        });
+    clf2.fit(raw.Xv, raw.yv, raw.features, raw.className, raw.states, raw.smoothing);
+    auto score2 = clf2.score(raw.Xv, raw.yv);
+    REQUIRE(score2 == Catch::Approx(0.973333).epsilon(raw.epsilon));
+}
+TEST_CASE("TAN & SPODE with invalid hyperparameters", "[Models]")
+{
+    auto raw = RawDatasets("iris", true);
+    auto clf = bayesnet::TAN();
+    clf.setHyperparameters({
+        {"parent", 5},
+        });
+    REQUIRE_THROWS_AS(clf.fit(raw.Xv, raw.yv, raw.features, raw.className, raw.states, raw.smoothing), std::invalid_argument);
+    auto clf2 = bayesnet::SPODE(0);
+    clf2.setHyperparameters({
+        {"parent", 5},
+        });
+    REQUIRE_THROWS_AS(clf2.fit(raw.Xv, raw.yv, raw.features, raw.className, raw.states, raw.smoothing), std::invalid_argument);
 }

tests/TestBoostAODE.cc

@@ -7,7 +7,7 @@
 #include <type_traits>
 #include <catch2/catch_test_macros.hpp>
 #include <catch2/catch_approx.hpp>
-#include <catch2/generators/catch_generators.hpp>
+#include <catch2/generators/catch_generators.hpp> 
 #include <catch2/matchers/catch_matchers.hpp>
 #include "bayesnet/ensembles/BoostAODE.h"
 #include "TestUtils.h"