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diff --git a/src/main/java/org/apache/commons/math3/ml/distance/DistanceMeasure.java b/src/main/java/org/apache/commons/math3/ml/distance/DistanceMeasure.java
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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.math3.ml.distance;
+
+import java.io.Serializable;
+
+import org.apache.commons.math3.exception.DimensionMismatchException;
+
+/**
+ * Interface for distance measures of n-dimensional vectors.
+ *
+ * @since 3.2
+ */
+public interface DistanceMeasure extends Serializable {
+
+    /**
+     * Compute the distance between two n-dimensional vectors.
+     * <p>
+     * The two vectors are required to have the same dimension.
+     *
+     * @param a the first vector
+     * @param b the second vector
+     * @return the distance between the two vectors
+     * @throws DimensionMismatchException if the array lengths differ.
+     */
+    double compute(double[] a, double[] b) throws DimensionMismatchException;
+}