From 6b62ad95c348ca760774ddf31c8982bb8a3d1f61 Mon Sep 17 00:00:00 2001
From: Joel Therrien <joel@joeltherrien.ca>
Date: Fri, 6 Jul 2018 13:21:34 -0700
Subject: [PATCH] Add support for loading datasets by CSV files.

---
 pom.xml                                       |  28 +++++
 .../ca/joeltherrien/randomforest/Main.java    | 105 ++++++++++++++++++
 .../joeltherrien/randomforest/Settings.java   |   7 +-
 .../covariates/BooleanCovariate.java          |  17 +++
 .../covariates/BooleanCovariateSettings.java  |   2 +-
 .../randomforest/covariates/Covariate.java    |   8 ++
 .../covariates/CovariateSettings.java         |   2 +-
 .../covariates/FactorCovariateSettings.java   |   2 +-
 .../covariates/NumericCovariate.java          |   9 ++
 .../covariates/NumericCovariateSettings.java  |   2 +-
 .../regression/MeanGroupDifferentiator.java   |   5 +
 .../regression/MeanResponseCombiner.java      |   4 +
 .../WeightedVarianceGroupDifferentiator.java  |   4 +
 .../randomforest/tree/ForestTrainer.java      |  17 +++
 .../tree/GroupDifferentiator.java             |  10 ++
 .../randomforest/tree/ResponseCombiner.java   |  12 ++
 .../randomforest/tree/TreeTrainer.java        |  11 ++
 .../randomforest/csv/TestLoadingCSV.java      |  66 +++++++++++
 .../settings/TestPersistence.java             |   3 +
 src/test/resources/testCSV.csv                |   4 +
 20 files changed, 313 insertions(+), 5 deletions(-)
 create mode 100644 src/main/java/ca/joeltherrien/randomforest/Main.java
 create mode 100644 src/test/java/ca/joeltherrien/randomforest/csv/TestLoadingCSV.java
 create mode 100644 src/test/resources/testCSV.csv

diff --git a/pom.xml b/pom.xml
index 36c9a38..cdb9617 100644
--- a/pom.xml
+++ b/pom.xml
@@ -58,5 +58,33 @@
 
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <mainClass>ca.joeltherrien.randomforest.Main</mainClass>
+                        </manifest>
+                    </archive>
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id> <!-- this is used for inheritance merges -->
+                        <phase>package</phase> <!-- bind to the packaging phase -->
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+
 
 </project>
\ No newline at end of file
diff --git a/src/main/java/ca/joeltherrien/randomforest/Main.java b/src/main/java/ca/joeltherrien/randomforest/Main.java
new file mode 100644
index 0000000..f557663
--- /dev/null
+++ b/src/main/java/ca/joeltherrien/randomforest/Main.java
@@ -0,0 +1,105 @@
+package ca.joeltherrien.randomforest;
+
+import ca.joeltherrien.randomforest.covariates.BooleanCovariateSettings;
+import ca.joeltherrien.randomforest.covariates.Covariate;
+import ca.joeltherrien.randomforest.covariates.FactorCovariateSettings;
+import ca.joeltherrien.randomforest.covariates.NumericCovariateSettings;
+import ca.joeltherrien.randomforest.tree.ForestTrainer;
+import org.apache.commons.csv.CSVFormat;
+import org.apache.commons.csv.CSVParser;
+import org.apache.commons.csv.CSVRecord;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.Reader;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        if(args.length != 1){
+            System.out.println("Must provide one argument - the path to the settings.yaml file.");
+            if(args.length == 0){
+                System.out.println("Generating template file.");
+                defaultTemplate().save(new File("template.yaml"));
+            }
+            return;
+        }
+        final File settingsFile = new File(args[0]);
+        final Settings settings = Settings.load(settingsFile);
+
+        final List<Covariate> covariates = settings.getCovariates().stream()
+                .map(cs -> cs.build()).collect(Collectors.toList());
+
+        final List<Row<Double>> dataset = loadData(covariates, settings);
+
+        final ForestTrainer<Double> forestTrainer = new ForestTrainer<>(settings, dataset, covariates);
+
+        if(settings.isSaveProgress()){
+            forestTrainer.trainParallelOnDisk(settings.getNumberOfThreads());
+        }
+        else{
+            forestTrainer.trainParallelInMemory(settings.getNumberOfThreads());
+        }
+
+
+    }
+
+
+    public static List<Row<Double>> loadData(final List<Covariate> covariates, final Settings settings) throws IOException {
+
+        final List<Row<Double>> dataset = new ArrayList<>();
+
+        final Reader input = new FileReader(settings.getDataFileLocation());
+        final CSVParser parser = CSVFormat.RFC4180.withFirstRecordAsHeader().parse(input);
+
+
+        int id = 1;
+        for(final CSVRecord record : parser){
+            final Map<String, Covariate.Value> covariateValueMap = new HashMap<>();
+
+            for(final Covariate<?> covariate : covariates){
+                covariateValueMap.put(covariate.getName(), covariate.createValue(record.get(covariate.getName())));
+            }
+
+            final String yStr = record.get(settings.getYVar());
+            final Double yNum = Double.parseDouble(yStr);
+
+            dataset.add(new Row<>(covariateValueMap, id++, yNum));
+
+        }
+
+        return dataset;
+
+    }
+
+    private static Settings defaultTemplate(){
+        return Settings.builder()
+                .covariates(List.of(
+                        new NumericCovariateSettings("x1"),
+                        new BooleanCovariateSettings("x2"),
+                        new FactorCovariateSettings("x3", List.of("cat", "mouse", "dog"))
+                        )
+                )
+                .yVar("y")
+                .dataFileLocation("data.csv")
+                .groupDifferentiator("WeightedVarianceGroupDifferentiator")
+                .responseCombiner("MeanResponseCombiner")
+                .treeResponseCombiner("MeanResponseCombiner")
+                .maxNodeDepth(100000)
+                .mtry(2)
+                .nodeSize(5)
+                .ntree(500)
+                .numberOfSplits(5)
+                .numberOfThreads(1)
+                .saveProgress(true)
+                .saveTreeLocation("trees/")
+                .build();
+    }
+
+}
diff --git a/src/main/java/ca/joeltherrien/randomforest/Settings.java b/src/main/java/ca/joeltherrien/randomforest/Settings.java
index bf3985a..da24933 100644
--- a/src/main/java/ca/joeltherrien/randomforest/Settings.java
+++ b/src/main/java/ca/joeltherrien/randomforest/Settings.java
@@ -2,6 +2,9 @@ package ca.joeltherrien.randomforest;
 
 import ca.joeltherrien.randomforest.covariates.Covariate;
 import ca.joeltherrien.randomforest.covariates.CovariateSettings;
+import ca.joeltherrien.randomforest.regression.MeanResponseCombiner;
+import ca.joeltherrien.randomforest.tree.GroupDifferentiator;
+import ca.joeltherrien.randomforest.tree.ResponseCombiner;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import lombok.*;
@@ -9,7 +12,9 @@ import lombok.*;
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * This class is saved & loaded using a saved configuration file. It contains all relevant settings when training a forest.
@@ -29,6 +34,7 @@ public class Settings {
     private String treeResponseCombiner;
 
     private List<CovariateSettings> covariates = new ArrayList<>();
+    private String yVar = "y";
 
     // number of covariates to randomly try
     private int mtry = 0;
@@ -64,5 +70,4 @@ public class Settings {
         mapper.writeValue(file, this);
     }
 
-
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariate.java b/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariate.java
index 6c6548d..9b5250e 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariate.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariate.java
@@ -25,6 +25,23 @@ public final class BooleanCovariate implements Covariate<Boolean>{
         return new BooleanValue(value);
     }
 
+    @Override
+    public Value<Boolean> createValue(String value) {
+        if(value == null || value.equalsIgnoreCase("na")){
+            return createValue( (Boolean) null);
+        }
+
+        if(value.equalsIgnoreCase("true")){
+            return createValue(true);
+        }
+        else if(value.equalsIgnoreCase("false")){
+            return createValue(false);
+        }
+        else{
+            throw new IllegalArgumentException("Require either true/false/na to create BooleanCovariate");
+        }
+    }
+
     public class BooleanValue implements Value<Boolean>{
 
         private final Boolean value;
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariateSettings.java b/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariateSettings.java
index 2bf6263..ed384f3 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariateSettings.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/BooleanCovariateSettings.java
@@ -12,7 +12,7 @@ public final class BooleanCovariateSettings extends CovariateSettings<Boolean> {
     }
 
     @Override
-    BooleanCovariate build() {
+    public BooleanCovariate build() {
         return new BooleanCovariate(name);
     }
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/Covariate.java b/src/main/java/ca/joeltherrien/randomforest/covariates/Covariate.java
index 75bc672..e7a5aef 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/Covariate.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/Covariate.java
@@ -16,6 +16,14 @@ public interface Covariate<V> extends Serializable {
 
     Value<V> createValue(V value);
 
+    /**
+     * Creates a Value of the appropriate type from a String; primarily used when parsing CSVs.
+     *
+     * @param value
+     * @return
+     */
+    Value<V> createValue(String value);
+
     interface Value<V> extends Serializable{
 
         Covariate<V> getParent();
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/CovariateSettings.java b/src/main/java/ca/joeltherrien/randomforest/covariates/CovariateSettings.java
index baafe4c..1418428 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/CovariateSettings.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/CovariateSettings.java
@@ -29,5 +29,5 @@ public abstract class CovariateSettings<V> {
         this.name = name;
     }
 
-    abstract Covariate<V> build();
+    public abstract Covariate<V> build();
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/FactorCovariateSettings.java b/src/main/java/ca/joeltherrien/randomforest/covariates/FactorCovariateSettings.java
index 04d4bb8..dbfaaae 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/FactorCovariateSettings.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/FactorCovariateSettings.java
@@ -18,7 +18,7 @@ public final class FactorCovariateSettings extends CovariateSettings<String> {
     }
 
     @Override
-    FactorCovariate build() {
+    public FactorCovariate build() {
         return new FactorCovariate(name, levels);
     }
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariate.java b/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariate.java
index 6bed687..2746697 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariate.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariate.java
@@ -55,6 +55,15 @@ public final class NumericCovariate implements Covariate<Double>{
         return new NumericValue(value);
     }
 
+    @Override
+    public Value<Double> createValue(String value) {
+        if(value == null || value.equalsIgnoreCase("na")){
+            return createValue((Double) null);
+        }
+
+        return createValue(Double.parseDouble(value));
+    }
+
     public class NumericValue implements Covariate.Value<Double>{
 
         private final Double value; // may be null
diff --git a/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariateSettings.java b/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariateSettings.java
index 0be6cf0..b35a81a 100644
--- a/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariateSettings.java
+++ b/src/main/java/ca/joeltherrien/randomforest/covariates/NumericCovariateSettings.java
@@ -12,7 +12,7 @@ public final class NumericCovariateSettings extends CovariateSettings<Double> {
     }
 
     @Override
-    NumericCovariate build() {
+    public NumericCovariate build() {
         return new NumericCovariate(name);
     }
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/regression/MeanGroupDifferentiator.java b/src/main/java/ca/joeltherrien/randomforest/regression/MeanGroupDifferentiator.java
index 7c196e6..da3b0b1 100644
--- a/src/main/java/ca/joeltherrien/randomforest/regression/MeanGroupDifferentiator.java
+++ b/src/main/java/ca/joeltherrien/randomforest/regression/MeanGroupDifferentiator.java
@@ -1,11 +1,16 @@
 package ca.joeltherrien.randomforest.regression;
 
 import ca.joeltherrien.randomforest.tree.GroupDifferentiator;
+import ca.joeltherrien.randomforest.tree.ResponseCombiner;
 
 import java.util.List;
 
 public class MeanGroupDifferentiator implements GroupDifferentiator<Double> {
 
+    static{
+        GroupDifferentiator.registerGroupDifferentiator("MeanGroupDifferentiator", new MeanGroupDifferentiator());
+    }
+
     @Override
     public Double differentiate(List<Double> leftHand, List<Double> rightHand) {
 
diff --git a/src/main/java/ca/joeltherrien/randomforest/regression/MeanResponseCombiner.java b/src/main/java/ca/joeltherrien/randomforest/regression/MeanResponseCombiner.java
index 57a3b35..3ff43f3 100644
--- a/src/main/java/ca/joeltherrien/randomforest/regression/MeanResponseCombiner.java
+++ b/src/main/java/ca/joeltherrien/randomforest/regression/MeanResponseCombiner.java
@@ -17,6 +17,10 @@ import java.util.function.Supplier;
  */
 public class MeanResponseCombiner implements ResponseCombiner<Double, MeanResponseCombiner.Container> {
 
+    static{
+        ResponseCombiner.registerResponseCombiner("MeanResponseCombiner", new MeanResponseCombiner());
+    }
+
     @Override
     public Double combine(List<Double> responses) {
         double size = responses.size();
diff --git a/src/main/java/ca/joeltherrien/randomforest/regression/WeightedVarianceGroupDifferentiator.java b/src/main/java/ca/joeltherrien/randomforest/regression/WeightedVarianceGroupDifferentiator.java
index 2f40999..c27363f 100644
--- a/src/main/java/ca/joeltherrien/randomforest/regression/WeightedVarianceGroupDifferentiator.java
+++ b/src/main/java/ca/joeltherrien/randomforest/regression/WeightedVarianceGroupDifferentiator.java
@@ -6,6 +6,10 @@ import java.util.List;
 
 public class WeightedVarianceGroupDifferentiator implements GroupDifferentiator<Double> {
 
+    static{
+        GroupDifferentiator.registerGroupDifferentiator("WeightedVarianceGroupDifferentiator", new WeightedVarianceGroupDifferentiator());
+    }
+
     @Override
     public Double differentiate(List<Double> leftHand, List<Double> rightHand) {
 
diff --git a/src/main/java/ca/joeltherrien/randomforest/tree/ForestTrainer.java b/src/main/java/ca/joeltherrien/randomforest/tree/ForestTrainer.java
index 76d4a70..f04a2f2 100644
--- a/src/main/java/ca/joeltherrien/randomforest/tree/ForestTrainer.java
+++ b/src/main/java/ca/joeltherrien/randomforest/tree/ForestTrainer.java
@@ -1,8 +1,11 @@
 package ca.joeltherrien.randomforest.tree;
 
 import ca.joeltherrien.randomforest.Bootstrapper;
+import ca.joeltherrien.randomforest.Settings;
 import ca.joeltherrien.randomforest.covariates.Covariate;
 import ca.joeltherrien.randomforest.Row;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
 import lombok.Builder;
 
 import java.io.FileOutputStream;
@@ -18,6 +21,7 @@ import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 @Builder
+@AllArgsConstructor(access=AccessLevel.PRIVATE)
 public class ForestTrainer<Y> {
 
     private final TreeTrainer<Y> treeTrainer;
@@ -34,6 +38,19 @@ public class ForestTrainer<Y> {
     private final boolean displayProgress;
     private final String saveTreeLocation;
 
+    public ForestTrainer(final Settings settings, final List<Row<Y>> data, final List<Covariate> covariates){
+        this.mtry = settings.getMtry();
+        this.ntree = settings.getNtree();
+        this.data = data;
+        this.displayProgress = true;
+        this.saveTreeLocation = settings.getSaveTreeLocation();
+
+        this.covariatesToTry = covariates;
+        this.treeResponseCombiner = ResponseCombiner.loadResponseCombinerByName(settings.getTreeResponseCombiner());
+        this.treeTrainer = new TreeTrainer<>(settings);
+
+    }
+
     public Forest<Y> trainSerial(){
 
         final List<Node<Y>> trees = new ArrayList<>(ntree);
diff --git a/src/main/java/ca/joeltherrien/randomforest/tree/GroupDifferentiator.java b/src/main/java/ca/joeltherrien/randomforest/tree/GroupDifferentiator.java
index cbd1247..8950aa8 100644
--- a/src/main/java/ca/joeltherrien/randomforest/tree/GroupDifferentiator.java
+++ b/src/main/java/ca/joeltherrien/randomforest/tree/GroupDifferentiator.java
@@ -1,6 +1,8 @@
 package ca.joeltherrien.randomforest.tree;
 
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * When choosing an optimal node to split on, we choose the split that maximizes the difference between the two groups.
@@ -12,4 +14,12 @@ public interface GroupDifferentiator<Y> {
 
     Double differentiate(List<Y> leftHand, List<Y> rightHand);
 
+    Map<String, GroupDifferentiator> GROUP_DIFFERENTIATOR_MAP = new HashMap<>();
+    static GroupDifferentiator loadGroupDifferentiatorByName(final String name){
+        return GROUP_DIFFERENTIATOR_MAP.get(name);
+    }
+    static void registerGroupDifferentiator(final String name, final GroupDifferentiator groupDifferentiator){
+        GROUP_DIFFERENTIATOR_MAP.put(name, groupDifferentiator);
+    }
+
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/tree/ResponseCombiner.java b/src/main/java/ca/joeltherrien/randomforest/tree/ResponseCombiner.java
index bbcdd30..6430aa0 100644
--- a/src/main/java/ca/joeltherrien/randomforest/tree/ResponseCombiner.java
+++ b/src/main/java/ca/joeltherrien/randomforest/tree/ResponseCombiner.java
@@ -1,10 +1,22 @@
 package ca.joeltherrien.randomforest.tree;
 
+import ca.joeltherrien.randomforest.regression.MeanResponseCombiner;
+
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collector;
 
 public interface ResponseCombiner<Y, K> extends Collector<Y, K, Y> {
 
     Y combine(List<Y> responses);
 
+    final static Map<String, ResponseCombiner> RESPONSE_COMBINER_MAP = new HashMap<>();
+    static ResponseCombiner loadResponseCombinerByName(final String name){
+        return RESPONSE_COMBINER_MAP.get(name);
+    }
+    static void registerResponseCombiner(final String name, final ResponseCombiner responseCombiner){
+        RESPONSE_COMBINER_MAP.put(name, responseCombiner);
+    }
+
 }
diff --git a/src/main/java/ca/joeltherrien/randomforest/tree/TreeTrainer.java b/src/main/java/ca/joeltherrien/randomforest/tree/TreeTrainer.java
index fd83382..d447952 100644
--- a/src/main/java/ca/joeltherrien/randomforest/tree/TreeTrainer.java
+++ b/src/main/java/ca/joeltherrien/randomforest/tree/TreeTrainer.java
@@ -2,12 +2,15 @@ package ca.joeltherrien.randomforest.tree;
 
 import ca.joeltherrien.randomforest.*;
 import ca.joeltherrien.randomforest.covariates.Covariate;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
 import lombok.Builder;
 
 import java.util.*;
 import java.util.stream.Collectors;
 
 @Builder
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
 public class TreeTrainer<Y> {
 
     private final ResponseCombiner<Y, ?> responseCombiner;
@@ -21,6 +24,14 @@ public class TreeTrainer<Y> {
     private final int nodeSize;
     private final int maxNodeDepth;
 
+    public TreeTrainer(final Settings settings){
+        this.numberOfSplits = settings.getNumberOfSplits();
+        this.nodeSize = settings.getNodeSize();
+        this.maxNodeDepth = settings.getMaxNodeDepth();
+
+        this.responseCombiner = ResponseCombiner.loadResponseCombinerByName(settings.getResponseCombiner());
+        this.groupDifferentiator = GroupDifferentiator.loadGroupDifferentiatorByName(settings.getGroupDifferentiator());
+    }
 
     public Node<Y> growTree(List<Row<Y>> data, List<Covariate> covariatesToTry){
         return growNode(data, covariatesToTry, 0);
diff --git a/src/test/java/ca/joeltherrien/randomforest/csv/TestLoadingCSV.java b/src/test/java/ca/joeltherrien/randomforest/csv/TestLoadingCSV.java
new file mode 100644
index 0000000..5a1faf7
--- /dev/null
+++ b/src/test/java/ca/joeltherrien/randomforest/csv/TestLoadingCSV.java
@@ -0,0 +1,66 @@
+package ca.joeltherrien.randomforest.csv;
+
+import ca.joeltherrien.randomforest.Main;
+import ca.joeltherrien.randomforest.Row;
+import ca.joeltherrien.randomforest.Settings;
+import ca.joeltherrien.randomforest.covariates.BooleanCovariateSettings;
+import ca.joeltherrien.randomforest.covariates.Covariate;
+import ca.joeltherrien.randomforest.covariates.FactorCovariateSettings;
+import ca.joeltherrien.randomforest.covariates.NumericCovariateSettings;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class TestLoadingCSV {
+
+    /*
+        y,x1,x2,x3
+        5,3.0,"mouse",true
+        2,1.0,"dog",false
+        9,1.5,"cat",true
+     */
+
+    @Test
+    public void verifyLoading() throws IOException {
+        final Settings settings = Settings.builder()
+                .dataFileLocation("src/test/resources/testCSV.csv")
+                .covariates(
+                        List.of(new NumericCovariateSettings("x1"),
+                                new FactorCovariateSettings("x2", List.of("dog", "cat", "mouse")),
+                                new BooleanCovariateSettings("x3"))
+                )
+                .yVar("y")
+                .build();
+
+        final List<Covariate> covariates = settings.getCovariates().stream()
+                .map(cs -> cs.build()).collect(Collectors.toList());
+
+        final List<Row<Double>> data = Main.loadData(covariates, settings);
+
+        assertEquals(3, data.size());
+
+        Row<Double> row = data.get(0);
+        assertEquals(5.0, (double)row.getResponse());
+        assertEquals(3.0, row.getCovariateValue("x1").getValue());
+        assertEquals("mouse", row.getCovariateValue("x2").getValue());
+        assertEquals(true, row.getCovariateValue("x3").getValue());
+
+        row = data.get(1);
+        assertEquals(2.0, (double)row.getResponse());
+        assertEquals(1.0, row.getCovariateValue("x1").getValue());
+        assertEquals("dog", row.getCovariateValue("x2").getValue());
+        assertEquals(false, row.getCovariateValue("x3").getValue());
+
+        row = data.get(2);
+        assertEquals(9.0, (double)row.getResponse());
+        assertEquals(1.5, row.getCovariateValue("x1").getValue());
+        assertEquals("cat", row.getCovariateValue("x2").getValue());
+        assertEquals(true, row.getCovariateValue("x3").getValue());
+
+    }
+
+}
diff --git a/src/test/java/ca/joeltherrien/randomforest/settings/TestPersistence.java b/src/test/java/ca/joeltherrien/randomforest/settings/TestPersistence.java
index 562df01..421ca65 100644
--- a/src/test/java/ca/joeltherrien/randomforest/settings/TestPersistence.java
+++ b/src/test/java/ca/joeltherrien/randomforest/settings/TestPersistence.java
@@ -4,6 +4,8 @@ import ca.joeltherrien.randomforest.Settings;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import ca.joeltherrien.randomforest.covariates.*;
+import ca.joeltherrien.randomforest.regression.MeanResponseCombiner;
+import ca.joeltherrien.randomforest.regression.WeightedVarianceGroupDifferentiator;
 import org.junit.jupiter.api.Test;
 
 import java.io.File;
@@ -22,6 +24,7 @@ public class TestPersistence {
                         new FactorCovariateSettings("x3", List.of("cat", "mouse", "dog"))
                         )
                 )
+                .yVar("y")
                 .dataFileLocation("data.csv")
                 .groupDifferentiator("WeightedVarianceGroupDifferentiator")
                 .responseCombiner("MeanResponseCombiner")
diff --git a/src/test/resources/testCSV.csv b/src/test/resources/testCSV.csv
new file mode 100644
index 0000000..ca1d181
--- /dev/null
+++ b/src/test/resources/testCSV.csv
@@ -0,0 +1,4 @@
+y,x1,x2,x3
+5,3.0,"mouse",true
+2,1.0,"dog",false
+9,1.5,"cat",true
\ No newline at end of file