Check-in commons-math 3.6.1

This includes many changes over the original version and is
also incompatible, which is why the existing commons-math library
is left untouched.

Test: N/A
Change-Id: Icd0f3069a3c62b2572f2263732d91e6c3b6e8cba

1 files changed, 35 insertions, 0 deletions

diff --git a/src/main/java/org/apache/commons/math3/analysis/TrivariateFunction.java b/src/main/java/org/apache/commons/math3/analysis/TrivariateFunction.java
new file mode 100644
index 0000000..30ba767
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/analysis/TrivariateFunction.java
@@ -0,0 +1,35 @@
+/*
+ * 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.analysis;
+
+/**
+ * An interface representing a trivariate real function.
+ *
+ * @since 2.2
+ */
+public interface TrivariateFunction {
+    /**
+     * Compute the value for the function.
+     *
+     * @param x x-coordinate for which the function value should be computed.
+     * @param y y-coordinate for which the function value should be computed.
+     * @param z z-coordinate for which the function value should be computed.
+     * @return the value.
+     */
+    double value(double x, double y, double z);
+}