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| 1 | +/* Copyright 2020 The TensorFlow Authors. All Rights Reserved. |
| 2 | +
|
| 3 | +Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | +you may not use this file except in compliance with the License. |
| 5 | +You may obtain a copy of the License at |
| 6 | +
|
| 7 | + http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +
|
| 9 | +Unless required by applicable law or agreed to in writing, software |
| 10 | +distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | +See the License for the specific language governing permissions and |
| 13 | +limitations under the License. |
| 14 | +=======================================================================*/ |
| 15 | +package org.tensorflow.framework.losses; |
| 16 | + |
| 17 | +import org.tensorflow.Operand; |
| 18 | +import org.tensorflow.framework.losses.impl.LossesHelper; |
| 19 | +import org.tensorflow.op.Ops; |
| 20 | +import org.tensorflow.types.family.TNumber; |
| 21 | + |
| 22 | +import static org.tensorflow.framework.utils.CastHelper.cast; |
| 23 | + |
| 24 | +/** |
| 25 | + * Computes the cross-entropy loss between true labels and predicted labels. |
| 26 | + * |
| 27 | + * <p>Use this cross-entropy loss when there are only two label classes (assumed to be 0 and 1). For |
| 28 | + * each example, there should be a single floating-point value per prediction. |
| 29 | + * |
| 30 | + * <p>Standalone usage: |
| 31 | + * |
| 32 | + * <pre> |
| 33 | + * Operand<TFloat32> labels = |
| 34 | + * tf.constant(new float[][] {{0.f, 1.f}, {0.f, 0.f}}); |
| 35 | + * Operand<TFloat32> predictions = |
| 36 | + * tf.constant(new float[][] {{0.6f, 0.4f}, {0.4f, 0.6f}}); |
| 37 | + * BinaryCrossentropy bce = new BinaryCrossentropy(tf); |
| 38 | + * Operand<TFloat32> result = bce.call(labels, predictions); |
| 39 | + * // produces 0.815 |
| 40 | + * </pre> |
| 41 | + * |
| 42 | + * <p>Calling with sample weight: |
| 43 | + * |
| 44 | + * <pre> |
| 45 | + * Operand<TFloat32> sampleWeight = tf.constant(new float[] {1.f, 0.f}); |
| 46 | + * Operand<TFloat32> result = bce.call(labels, predictions, sampleWeight); |
| 47 | + * // produces 0.458f |
| 48 | + * </pre> |
| 49 | + * |
| 50 | + * <p>Using <code>SUM</code> reduction type: |
| 51 | + * |
| 52 | + * <pre> |
| 53 | + * BinaryCrossentropy bce = new BinaryCrossentropy(tf, Reduction.SUM); |
| 54 | + * Operand<TFloat32> result = bce.call(labels, predictions); |
| 55 | + * // produces 1.630f |
| 56 | + * </pre> |
| 57 | + * |
| 58 | + * <p>Using <code>NONE</code> reduction type: |
| 59 | + * |
| 60 | + * <pre> |
| 61 | + * BinaryCrossentropy bce = new BinaryCrossentropy(tf, Reduction.NONE); |
| 62 | + * Operand<TFloat32> result = bce.call(labels, predictions); |
| 63 | + * // produces [0.916f, 0.714f] |
| 64 | + * </pre> |
| 65 | + */ |
| 66 | +public class BinaryCrossentropy extends Loss { |
| 67 | + public static final boolean FROM_LOGITS_DEFAULT = false; |
| 68 | + public static final float LABEL_SMOOTHING_DEFAULT = 0.0f; |
| 69 | + |
| 70 | + private final boolean fromLogits; |
| 71 | + private final float labelSmoothing; |
| 72 | + |
| 73 | + /** |
| 74 | + * Creates a Binary Crossentropy Loss using {@link Class#getSimpleName()} as the loss name, {@link |
| 75 | + * #FROM_LOGITS_DEFAULT} for fromLogits, {@link #LABEL_SMOOTHING_DEFAULT} for labelSmoothing and a |
| 76 | + * Loss Reduction of {@link Loss#REDUCTION_DEFAULT} |
| 77 | + * |
| 78 | + * @param tf the TensorFlow Ops |
| 79 | + */ |
| 80 | + public BinaryCrossentropy(Ops tf) { |
| 81 | + this(tf, null, FROM_LOGITS_DEFAULT, LABEL_SMOOTHING_DEFAULT, REDUCTION_DEFAULT); |
| 82 | + } |
| 83 | + |
| 84 | + /** |
| 85 | + * Creates a Binary Crossentropy loss using {@link Class#getSimpleName()} as the loss name, {@link |
| 86 | + * #FROM_LOGITS_DEFAULT} for fromLogits, and {@link #LABEL_SMOOTHING_DEFAULT} for labelSmoothing |
| 87 | + * |
| 88 | + * @param tf the TensorFlow Ops |
| 89 | + * @param reduction Type of Reduction to apply to the loss. |
| 90 | + */ |
| 91 | + public BinaryCrossentropy(Ops tf, Reduction reduction) { |
| 92 | + this(tf, null, FROM_LOGITS_DEFAULT, LABEL_SMOOTHING_DEFAULT, reduction); |
| 93 | + } |
| 94 | + |
| 95 | + /** |
| 96 | + * Creates a Binary Crossentropy loss using using {@link Class#getSimpleName()} as the loss name, |
| 97 | + * labelSmoothing of {@link #LABEL_SMOOTHING_DEFAULT}, a reduction of {@link |
| 98 | + * Loss#REDUCTION_DEFAULT}, |
| 99 | + * |
| 100 | + * @param tf the TensorFlow Ops |
| 101 | + * @param fromLogits Whether to interpret predictions as a tensor of logit values |
| 102 | + */ |
| 103 | + public BinaryCrossentropy(Ops tf, boolean fromLogits) { |
| 104 | + this(tf, null, fromLogits, LABEL_SMOOTHING_DEFAULT, REDUCTION_DEFAULT); |
| 105 | + } |
| 106 | + |
| 107 | + /** |
| 108 | + * Creates a Binary Crossentropy loss using labelSmoothing of {@link #LABEL_SMOOTHING_DEFAULT} a |
| 109 | + * reduction of {@link Loss#REDUCTION_DEFAULT}. |
| 110 | + * |
| 111 | + * @param tf the TensorFlow Ops |
| 112 | + * @param name the name of the loss |
| 113 | + * @param fromLogits Whether to interpret predictions as a tensor of logit values |
| 114 | + */ |
| 115 | + public BinaryCrossentropy(Ops tf, String name, boolean fromLogits) { |
| 116 | + this(tf, name, fromLogits, LABEL_SMOOTHING_DEFAULT, REDUCTION_DEFAULT); |
| 117 | + } |
| 118 | + |
| 119 | + /** |
| 120 | + * Creates a Binary Crossentropy loss using using {@link Class#getSimpleName()} as the loss name, |
| 121 | + * and a reduction of {@link Loss#REDUCTION_DEFAULT}. |
| 122 | + * |
| 123 | + * @param tf the TensorFlow Ops |
| 124 | + * @param fromLogits Whether to interpret predictions as a tensor of logit values |
| 125 | + * @param labelSmoothing A number in the range, [0, 1]. When 0, no smoothing occurs. When > 0, |
| 126 | + * compute the loss between the predicted labels and a smoothed version of the true labels, |
| 127 | + * where the smoothing squeezes the labels towards 0.5. Larger values of labelSmoothing |
| 128 | + * correspond to heavier smoothing. |
| 129 | + */ |
| 130 | + public BinaryCrossentropy(Ops tf, boolean fromLogits, float labelSmoothing) { |
| 131 | + this(tf, null, fromLogits, labelSmoothing, REDUCTION_DEFAULT); |
| 132 | + } |
| 133 | + |
| 134 | + /** |
| 135 | + * Creates a Binary Crossentropy loss using a reduction of {@link Loss#REDUCTION_DEFAULT}. |
| 136 | + * |
| 137 | + * @param tf the TensorFlow Ops |
| 138 | + * @param name the name of the loss |
| 139 | + * @param fromLogits Whether to interpret predictions as a tensor of logit values |
| 140 | + * @param labelSmoothing A number in the range, [0, 1]. When 0, no smoothing occurs. When > 0, |
| 141 | + * compute the loss between the predicted labels and a smoothed version of the true labels, |
| 142 | + * where the smoothing squeezes the labels towards 0.5. Larger values of labelSmoothing |
| 143 | + * correspond to heavier smoothing. |
| 144 | + */ |
| 145 | + public BinaryCrossentropy(Ops tf, String name, boolean fromLogits, float labelSmoothing) { |
| 146 | + this(tf, name, fromLogits, labelSmoothing, REDUCTION_DEFAULT); |
| 147 | + } |
| 148 | + |
| 149 | + /** |
| 150 | + * Creates a Binary Crossentropy loss |
| 151 | + * |
| 152 | + * @param tf the TensorFlow Ops |
| 153 | + * @param fromLogits Whether to interpret predictions as a tensor of logit values |
| 154 | + * @param labelSmoothing A number in the range, [0, 1]. When 0, no smoothing occurs. When > 0, |
| 155 | + * compute the loss between the predicted labels and a smoothed version of the true labels, |
| 156 | + * where the smoothing squeezes the labels towards 0.5. Larger values of labelSmoothing |
| 157 | + * correspond to heavier smoothing. |
| 158 | + * @param reduction Type of Reduction to apply to the loss. |
| 159 | + */ |
| 160 | + public BinaryCrossentropy(Ops tf, boolean fromLogits, float labelSmoothing, Reduction reduction) { |
| 161 | + this(tf, null, fromLogits, labelSmoothing, reduction); |
| 162 | + } |
| 163 | + |
| 164 | + /** |
| 165 | + * Creates a Binary Crossentropy loss |
| 166 | + * |
| 167 | + * @param tf the TensorFlow Ops |
| 168 | + * @param name the name of the loss |
| 169 | + * @param fromLogits Whether to interpret predictions as a tensor of logit values |
| 170 | + * @param labelSmoothing A number in the range, [0, 1]. When 0, no smoothing occurs. When > 0, |
| 171 | + * compute the loss between the predicted labels and a smoothed version of the true labels, |
| 172 | + * where the smoothing squeezes the labels towards 0.5. Larger values of labelSmoothing |
| 173 | + * correspond to heavier smoothing. |
| 174 | + * @param reduction Type of Reduction to apply to the loss. |
| 175 | + * @throws IllegalArgumentException if labelSmoothing is not in the inclusive range of 0. - 1. |
| 176 | + */ |
| 177 | + public BinaryCrossentropy( |
| 178 | + Ops tf, String name, boolean fromLogits, float labelSmoothing, Reduction reduction) { |
| 179 | + super(tf, name, reduction); |
| 180 | + if (labelSmoothing < 0 || labelSmoothing > 1) |
| 181 | + throw new IllegalArgumentException( |
| 182 | + "labelSmoothing must be >= 0. and <= 1, found " + labelSmoothing); |
| 183 | + this.fromLogits = fromLogits; |
| 184 | + this.labelSmoothing = labelSmoothing; |
| 185 | + } |
| 186 | + |
| 187 | + /** |
| 188 | + * Generates an Operand that calculates the loss. |
| 189 | + * |
| 190 | + * <p>If run in Graph mode, the computation will throw {@link |
| 191 | + * org.tensorflow.exceptions.TFInvalidArgumentException} if the predictions values are outside the |
| 192 | + * range o [0. to 1.]. In Eager Mode, this call will throw {@link IllegalArgumentException}, if |
| 193 | + * the predictions values are outside the range o [0. to 1.] |
| 194 | + * |
| 195 | + * @param labels the truth values or labels |
| 196 | + * @param predictions the predictions, values must be in the range [0. to 1.] inclusive. |
| 197 | + * @param sampleWeights Optional SampleWeights acts as a coefficient for the loss. If a scalar is |
| 198 | + * provided, then the loss is simply scaled by the given value. If SampleWeights is a tensor |
| 199 | + * of size [batch_size], then the total loss for each sample of the batch is rescaled by the |
| 200 | + * corresponding element in the SampleWeights vector. If the shape of SampleWeights is |
| 201 | + * [batch_size, d0, .. dN-1] (or can be broadcast to this shape), then each loss element of |
| 202 | + * predictions is scaled by the corresponding value of SampleWeights. (Note on dN-1: all loss |
| 203 | + * functions reduce by 1 dimension, usually axis=-1.) |
| 204 | + * @param <T> The data type of the predictions, sampleWeights and loss. |
| 205 | + * @param <U> The data type of the labels. |
| 206 | + * @return the loss |
| 207 | + * @throws IllegalArgumentException if the predictions are outside the range [0.-1.]. |
| 208 | + */ |
| 209 | + @Override |
| 210 | + public <T extends TNumber, U extends TNumber> Operand<T> call( |
| 211 | + Operand<U> labels, Operand<T> predictions, Operand<T> sampleWeights) { |
| 212 | + Operand<T> lPredictions; |
| 213 | + if (!fromLogits) { |
| 214 | + // add predictions range check for 0 - 1 |
| 215 | + lPredictions = |
| 216 | + LossesHelper.rangeCheck( |
| 217 | + getTF(), |
| 218 | + "predictions range check [0-1]", |
| 219 | + predictions, |
| 220 | + cast(getTF(), getTF().constant(0), predictions.asOutput().dataType()), |
| 221 | + cast(getTF(), getTF().constant(1), predictions.asOutput().dataType())); |
| 222 | + |
| 223 | + } else { |
| 224 | + lPredictions = predictions; |
| 225 | + } |
| 226 | + |
| 227 | + Operand<T> losses = |
| 228 | + Losses.binaryCrossentropy(getTF(), labels, lPredictions, fromLogits, labelSmoothing); |
| 229 | + return LossesHelper.computeWeightedLoss(getTF(), losses, getReduction(), sampleWeights); |
| 230 | + } |
| 231 | +} |
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