1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.math4.neuralnet.sofm;
19
20 /**
21 * Provides the learning rate as a function of the number of calls
22 * already performed during the learning task.
23 *
24 * @since 3.3
25 */
26 public interface LearningFactorFunction {
27 /**
28 * Computes the learning rate at the current call.
29 *
30 * @param numCall Current step of the training task.
31 * @return the value of the function at {@code numCall}.
32 */
33 double value(long numCall);
34 }