| /** |
| * 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.horn.funcs; |
| |
| import java.io.IOException; |
| |
| import org.apache.hama.commons.math.DenseFloatVector; |
| import org.apache.hama.commons.math.DoubleVector; |
| import org.apache.hama.commons.math.FloatFunction; |
| import org.apache.hama.commons.math.FloatVector; |
| import org.apache.horn.core.IntermediateOutput; |
| |
| public class SoftMax extends FloatFunction { |
| |
| @Override |
| public float apply(float value) { |
| // it will be handled by intermediate output handler |
| return value; |
| } |
| |
| @Override |
| public float applyDerivative(float value) { |
| return value * (1f - value); |
| } |
| |
| public static class SoftMaxOutputComputer extends IntermediateOutput { |
| |
| @Override |
| public FloatVector interlayer(FloatVector output) throws IOException { |
| FloatVector expVec = new DenseFloatVector(output.getDimension()); |
| float sum = 0.0f; |
| for(int i = 0; i < output.getDimension(); ++i) { |
| float exp = (float) Math.exp(output.get(i)); |
| sum += exp; |
| expVec.set(i, exp); |
| } |
| // divide by the sum of exponential of the whole vector |
| FloatVector softmaxed = expVec.divide(sum); |
| return softmaxed; |
| } |
| |
| } |
| |
| } |