# Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved. # # Licensed 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. """ All layers just related to metric. """ from __future__ import print_function import warnings from ..layer_helper import LayerHelper from ..initializer import Normal, Constant from ..framework import Variable from ..param_attr import ParamAttr from . import nn from ..data_feeder import check_type_and_dtype __all__ = ['accuracy', 'auc'] def accuracy(input, label, k=1, correct=None, total=None): """ accuracy layer. Refer to the https://en.wikipedia.org/wiki/Precision_and_recall This function computes the accuracy using the input and label. If the correct label occurs in top k predictions, then correct will increment by one. Note: the dtype of accuracy is determined by input. the input and label dtype can be different. Args: input(Variable): The input of accuracy layer, which is the predictions of network. A LoDTensor or Tensor with type float32,float64. label(Variable): The label of dataset. LoDTensor or Tensor with type int32,int64. k(int): The top k predictions for each class will be checked. Data type is int64 or int32. correct(Variable): The correct predictions count. A Tensor with type int64 or int32. total(Variable): The total entries count. A tensor with type int64 or int32. Returns: Variable: The correct rate. A Tensor with type float32. Examples: .. code-block:: python import paddle.fluid as fluid import numpy as np data = fluid.data(name="input", shape=[-1, 32, 32], dtype="float32") label = fluid.data(name="label", shape=[-1,1], dtype="int") fc_out = fluid.layers.fc(input=data, size=10) predict = fluid.layers.softmax(input=fc_out) result = fluid.layers.accuracy(input=predict, label=label, k=5) place = fluid.CPUPlace() exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) x = np.random.rand(3, 32, 32).astype("float32") y = np.array([[1],[0],[1]]) output= exe.run(feed={"input": x,"label": y}, fetch_list=[result[0]]) print(output) #[array([0.6666667], dtype=float32)] """ helper = LayerHelper("accuracy", **locals()) check_type_and_dtype(input, 'input', Variable, ['float16', 'float32', 'float64'], 'accuracy') topk_out, topk_indices = nn.topk(input, k=k) acc_out = helper.create_variable_for_type_inference(dtype="float32") if correct is None: correct = helper.create_variable_for_type_inference(dtype="int64") if total is None: total = helper.create_variable_for_type_inference(dtype="int64") helper.append_op( type="accuracy", inputs={ "Out": [topk_out], "Indices": [topk_indices], "Label": [label] }, outputs={ "Accuracy": [acc_out], "Correct": [correct], "Total": [total], }) return acc_out def auc(input, label, curve='ROC', num_thresholds=2**12 - 1, topk=1, slide_steps=1): """ **Area Under the Curve (AUC) Layer** This implementation computes the AUC according to forward output and label. It is used very widely in binary classification evaluation. Note: If input label contains values other than 0 and 1, it will be cast to `bool`. Find the relevant definitions `here `_. There are two types of possible curves: 1. ROC: Receiver operating characteristic; 2. PR: Precision Recall Args: input(Variable): A floating-point 2D Variable, values are in the range [0, 1]. Each row is sorted in descending order. This input should be the output of topk. Typically, this Variable indicates the probability of each label. A LoDTensor or Tensor with type float32,float64. label(Variable): A 2D int Variable indicating the label of the training data. The height is batch size and width is always 1. A LoDTensor or Tensor with type int32,int64. curve(str): Curve type, can be 'ROC' or 'PR'. Default 'ROC'. num_thresholds(int): The number of thresholds to use when discretizing the roc curve. Default 200. topk(int): only topk number of prediction output will be used for auc. slide_steps: when calc batch auc, we can not only use step currently but the previous steps can be used. slide_steps=1 means use the current step, slide_steps=3 means use current step and the previous second steps, slide_steps=0 use all of the steps. Returns: Variable: A tuple representing the current AUC. The return tuple is auc_out, batch_auc_out, [ batch_stat_pos, batch_stat_neg, stat_pos, stat_neg ] Data type is Tensor, supporting float32, float64. Examples: .. code-block:: python import paddle.fluid as fluid import numpy as np data = fluid.data(name="input", shape=[-1, 32,32], dtype="float32") label = fluid.data(name="label", shape=[-1], dtype="int") fc_out = fluid.layers.fc(input=data, size=2) predict = fluid.layers.softmax(input=fc_out) result=fluid.layers.auc(input=predict, label=label) place = fluid.CPUPlace() exe = fluid.Executor(place) exe.run(fluid.default_startup_program()) x = np.random.rand(3,32,32).astype("float32") y = np.array([1,0,1]) output= exe.run(feed={"input": x,"label": y}, fetch_list=[result[0]]) print(output) #[array([0.5])] """ helper = LayerHelper("auc", **locals()) auc_out = helper.create_variable_for_type_inference(dtype="float64") batch_auc_out = helper.create_variable_for_type_inference(dtype="float64") # make tp, tn, fp, fn persistable, so that can accumulate all batches. # for batch auc # we create slide_step+1 buckets, the first slide_steps buckets store # historical batch-level values, and the last bucket stores the sum values of # previous slide_step buckets. # The index of bucket that the newest batch will use is determined by batch_id mod slide_steps, # and batch_id is store in the last posision of following variable batch_stat_pos = helper.create_global_variable( persistable=True, dtype='int64', shape=[(1 + slide_steps) * (num_thresholds + 1) + 1]) batch_stat_neg = helper.create_global_variable( persistable=True, dtype='int64', shape=[(1 + slide_steps) * (num_thresholds + 1) + 1]) # for global auc # Needn't maintain the batch id stat_pos = helper.create_global_variable( persistable=True, dtype='int64', shape=[num_thresholds + 1]) stat_neg = helper.create_global_variable( persistable=True, dtype='int64', shape=[num_thresholds + 1]) for var in [batch_stat_pos, batch_stat_neg, stat_pos, stat_neg]: helper.set_variable_initializer( var, Constant( value=0.0, force_cpu=False)) # Batch AUC helper.append_op( type="auc", inputs={ "Predict": [input], "Label": [label], "StatPos": [batch_stat_pos], "StatNeg": [batch_stat_neg] }, attrs={ "curve": curve, "num_thresholds": num_thresholds, "slide_steps": slide_steps }, outputs={ "AUC": [batch_auc_out], "StatPosOut": [batch_stat_pos], "StatNegOut": [batch_stat_neg] }) # Global AUC helper.append_op( type="auc", inputs={ "Predict": [input], "Label": [label], "StatPos": [stat_pos], "StatNeg": [stat_neg] }, attrs={ "curve": curve, "num_thresholds": num_thresholds, "slide_steps": 0 }, outputs={ "AUC": [auc_out], "StatPosOut": [stat_pos], "StatNegOut": [stat_neg] }) return auc_out, batch_auc_out, [ batch_stat_pos, batch_stat_neg, stat_pos, stat_neg ]