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diff --git a/src/main/java/org/apache/commons/math3/distribution/MultivariateRealDistribution.java b/src/main/java/org/apache/commons/math3/distribution/MultivariateRealDistribution.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.distribution;
+
+import org.apache.commons.math3.exception.NotStrictlyPositiveException;
+
+/**
+ * Base interface for multivariate distributions on the reals.
+ *
+ * <p>This is based largely on the RealDistribution interface, but cumulative distribution functions
+ * are not required because they are often quite difficult to compute for multivariate
+ * distributions.
+ *
+ * @since 3.1
+ */
+public interface MultivariateRealDistribution {
+    /**
+     * Returns the probability density function (PDF) of this distribution evaluated at the
+     * specified point {@code x}. In general, the PDF is the derivative of the cumulative
+     * distribution function. If the derivative does not exist at {@code x}, then an appropriate
+     * replacement should be returned, e.g. {@code Double.POSITIVE_INFINITY}, {@code Double.NaN}, or
+     * the limit inferior or limit superior of the difference quotient.
+     *
+     * @param x Point at which the PDF is evaluated.
+     * @return the value of the probability density function at point {@code x}.
+     */
+    double density(double[] x);
+
+    /**
+     * Reseeds the random generator used to generate samples.
+     *
+     * @param seed Seed with which to initialize the random number generator.
+     */
+    void reseedRandomGenerator(long seed);
+
+    /**
+     * Gets the number of random variables of the distribution. It is the size of the array returned
+     * by the {@link #sample() sample} method.
+     *
+     * @return the number of variables.
+     */
+    int getDimension();
+
+    /**
+     * Generates a random value vector sampled from this distribution.
+     *
+     * @return a random value vector.
+     */
+    double[] sample();
+
+    /**
+     * Generates a list of a random value vectors from the distribution.
+     *
+     * @param sampleSize the number of random vectors to generate.
+     * @return an array representing the random samples.
+     * @throws org.apache.commons.math3.exception.NotStrictlyPositiveException if {@code sampleSize}
+     *     is not positive.
+     * @see #sample()
+     */
+    double[][] sample(int sampleSize) throws NotStrictlyPositiveException;
+}