Separating out the metrics.

Signed-off-by: jzonthemtn <[email protected]>

opensearch-search-quality-evaluation-plugin/src/main/java/org/opensearch/eval/metrics/DcgSearchMetric.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.eval.metrics;
+
+import java.util.List;
+
+public class DcgSearchMetric extends SearchMetric {
+
+    protected final List<Double> relevanceScores;
+
+    public DcgSearchMetric(final int k, final List<Double> relevanceScores) {
+        super(k);
+        this.relevanceScores = relevanceScores;
+    }
+
+    @Override
+    public String getName() {
+        return "dcg_at_" + k;
+    }
+
+    @Override
+    public double calculate() {
+
+        double dcg = 0.0;
+        for(int i = 0; i < relevanceScores.size(); i++) {
+            double relevance = relevanceScores.get(i);
+            dcg += relevance / Math.log(i + 2); // Add 2 to avoid log(1) = 0
+        }
+        return dcg;
+
+    }
+
+}

opensearch-search-quality-evaluation-plugin/src/main/java/org/opensearch/eval/metrics/NdcgSearchMetric.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.eval.metrics;
+
+import java.util.List;
+
+public class NdcgSearchMetric extends DcgSearchMetric {
+
+    private final List<Double> idealRelevanceScores;
+
+    public NdcgSearchMetric(final int k, final List<Double> relevanceScores, final List<Double> idealRelevanceScores) {
+        super(k, relevanceScores);
+        this.idealRelevanceScores = idealRelevanceScores;
+    }
+
+    @Override
+    public String getName() {
+        return "ndcg_at_" + k;
+    }
+
+    @Override
+    public double calculate() {
+
+        double dcg = super.calculate();
+
+        double idcg = 0.0;
+        for(int i = 0; i < idealRelevanceScores.size(); i++) {
+            double relevance = idealRelevanceScores.get(i);
+            idcg += relevance / Math.log(i + 2); // Add 2 to avoid log(1) = 0
+        }
+
+        if(idcg == 0) {
+            return 0;
+        }
+
+        return dcg / idcg;
+
+    }
+
+}

opensearch-search-quality-evaluation-plugin/src/main/java/org/opensearch/eval/metrics/PrecisionSearchMetric.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.eval.metrics;
+
+import java.util.List;
+
+public class PrecisionSearchMetric extends SearchMetric {
+
+    private final List<Double> relevanceScores;
+
+    public PrecisionSearchMetric(final int k, final List<Double> relevanceScores) {
+        super(k);
+        this.relevanceScores = relevanceScores;
+    }
+
+    @Override
+    public String getName() {
+        return "precision_at_" + k;
+    }
+
+    @Override
+    public double calculate() {
+
+        // TODO: Implement this.
+        return 0.0;
+
+    }
+
+}

opensearch-search-quality-evaluation-plugin/src/main/java/org/opensearch/eval/metrics/SearchMetric.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.eval.metrics;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public abstract class SearchMetric {
+
+    private static final Logger LOGGER = LogManager.getLogger(SearchMetric.class);
+
+    protected int k;
+
+    public abstract String getName();
+
+    public abstract double calculate();
+
+    public SearchMetric(final int k) {
+        this.k = k;
+    }
+
+    public int getK() {
+        return k;
+    }
+
+}