多标记学习指标（一篇博客就够了）

淡淡的烟草味﹌ 2022-12-04 09:25 86阅读 0赞

写作初心：代码写好了，评价指标很杂很乱，想写一个适合多标记学习或者多标记分类**评价指标的类-**实现各种常用指标，免得以后到处找，耗时耗力。更多可[参考][Link 1]

# ***目前已经实现指标（后续不断更新）：*** #

# 1 准确率-accuracy #

# 2   F1值 - fscore #

# 3 hamming\_loss -hamming\_distance #

# 4 AUROC #

# 5 AUPRC - (很多博客没有找到这个) #

# 6 查准率- avgPrecision #

Intuitively, precision is the ability of the classifier not to label as positive a sample that is negative, and recall is the ability of the classifier to find all the positive samples（查准率是分类器不把阴性样本标记为阳性的能力，而召回率是分类器找到所有阳性样本的能力。）2者都是越高越好.

个人关于查准率和召回率简记（都是基于多分类为背景），最好结合一个混淆矩阵读下面例子：

查准率：字面意思，希望查的越准越好，识别模型查的准不准。举个极端例子，模型预测该类99个样本为真（99/100， 100个样本下），但实际只有5个样本。此时prec= 5/99,  查准率就非常小了。说明模型查的不准，因为它把很多阴性样本标记为阳性样本。

召回率：字面意思，召回，希望召回产品越来越少（比如说，研制了A产品，公司觉得是好产品（你的模型预测为真），但是，消费者一使用，发现很多是坏的（实际是假），此时需要重新召回产品，重新修理，然后在给消费者。）。 召回率越高，说明公司真正召回产品的概率越低，即1-recall。

# 7 召回率 -avgRecall #

#  8 收敛 -coverage #

# 9 秩损失 -ranking\_loss #

# -*- coding: utf-8 -*-
    """
    Created on Sun Sep  6 20:38:38 2020
    
    @author ylyang
    """
    #from sklearn import datasets
    import sklearn
    #import torch 
    import numpy as np
    from scipy.sparse import csr_matrix
    from scipy.sparse.csgraph import laplacian
    from scipy.sparse.linalg import eigs
    from sklearn.metrics import accuracy_score
    from sklearn.metrics import f1_score
    from sklearn.metrics import hamming_loss
    from sklearn.metrics import roc_auc_score
    from sklearn.metrics import precision_score, recall_score,auc
    
    # np.set_printoptions(threshold='nan')
    class Metric(object):
        def __init__(self,output,label):
            self.output = output   #prediction label matric
            self.label = label    #true  label matric
    
        def accuracy_subset(self,threash=0.5):
            y_pred =self.output
            y_true = self.label
            y_pred=np.where(y_pred>threash,1,0)
            accuracy=accuracy_score(y_true,y_pred)
            return accuracy
        
        def accuracy_mean(self,threash=0.5):
            y_pred =self.output
            y_true = self.label      
            y_pred=np.where(y_pred>threash,1,0)
            accuracy=np.mean(np.equal(y_true,y_pred))
            return accuracy
        
        def accuracy_multiclass(self):
            y_pred =self.output
            y_true = self.label     
            accuracy=accuracy_score(np.argmax(y_pred,1),np.argmax(y_true,1))
            return accuracy
        
        def micfscore(self,threash=0.5,type='micro'):
            y_pred =self.output
            y_true = self.label
            y_pred=np.where(y_pred>threash,1,0)
            return f1_score(y_pred,y_true,average=type)
        def macfscore(self,threash=0.5,type='macro'):
            y_pred =self.output
            y_true = self.label
            y_pred=np.where(y_pred>threash,1,0)
            return f1_score(y_pred,y_true,average=type)
        
        def hamming_distance(self,threash=0.5):
            y_pred =self.output
            y_true = self.label
            y_pred=np.where(y_pred>threash,1,0)
            return hamming_loss(y_true,y_pred)
        
        def fscore_class(self,type='micro'):
            y_pred =self.output
            y_true = self.label
            return f1_score(np.argmax(y_pred,1),np.argmax(y_true,1),average=type)
        
        def auROC(self):
            y_pred =self.output
            y_true = self.label
            row,col = label.shape
            temp = []
            ROC = 0
            for i in range(col):
                sigle_ROC = roc_auc_score(y_true[:,i], y_pred[:,i], average='macro', sample_weight=None)
                #print("%d th AUROC: %f"%(i,ROC))   
                temp.append(sigle_ROC)
        
                ROC += sigle_ROC
            return ROC/(col)
        
        def MacroAUC(self):
            y_pred =self.output #num_instance*num_label
            y_true = self.label #num_instance*num_label 
            num_instance,num_class =   y_pred.shape
            count = np.zeros((num_class,1))   # store the number of postive instance'score>negative instance'score
            num_P_instance =  np.zeros((num_class,1)) #number of positive instance for every label      
            num_N_instance =  np.zeros((num_class,1)) 
            AUC = np.zeros((num_class,1))  # for each label
            count_valid_label = 0
            for  i in range(num_class): #第i类
                num_P_instance[i,0] = sum(y_true[:,i] == 1) #label,,test_target
                num_N_instance[i,0] = num_instance - num_P_instance[i,0]
                # exclude the label on which all instances are positive or negative,
                # leading to num_P_instance(i,1) or num_N_instance(i,1) is zero
                if num_P_instance[i,0] == 0 or num_N_instance[i,0] == 0:
                    AUC[i,0] = 0
                    count_valid_label = count_valid_label + 1
                else:
    
                    temp_P_Outputs = np.zeros((int(num_P_instance[i,0]), num_class))
                    temp_N_Outputs = np.zeros((int(num_N_instance[i,0]), num_class))
                    #
                    temp_P_Outputs[:,i] = y_pred[y_true[:,i]==1,i]
                    temp_N_Outputs[:,i] = y_pred[y_true[:,i]==0,i]    
                    for m in range(int(num_P_instance[i,0])):
                        for n in range(int(num_N_instance[i,0])):
                            if(temp_P_Outputs[m,i] > temp_N_Outputs[n,i] ):
                                count[i,0] = count[i,0] + 1
                            elif(temp_P_Outputs[m,i] == temp_N_Outputs[n,i]):
                                count[i,0] = count[i,0] + 0.5
                    
                    AUC[i,0] = count[i,0]/(num_P_instance[i,0]*num_N_instance[i,0])  
            macroAUC1 = sum(AUC)/(num_class-count_valid_label)
            return  float(macroAUC1),AUC    
        
        def avgPrecision(self):
            y_pred =self.output
            y_true = self.label
            num_instance,num_class =  y_pred.shape  
            precision_value = 0
            precisions = []
            for i in range(num_instance):
                p = precision_score(y_true[i,:], y_pred[i,:])
                precisions.append(p)
                precision_value += p
                #print(precision_value)
            pre_list = np.array([1.0] + precisions + [0.0] )#for get AUPRC
            #print(pre_list)
            return float(precision_value/num_instance), pre_list
            
        def avgRecall(self):
            y_pred =self.output
            y_true = self.label
            num_instance,num_class =  y_pred.shape  
            recall_value = 0
            recalls  = []
            for i in range(num_instance):
                p = recall_score(y_true[i,:], y_pred[i,:])
                recalls.append(p)
                recall_value += p
            rec_list = np.array([0.0] + recalls + [1.0]) #for get AUPRC
            sorting_indices = np.argsort(rec_list)    
            #print(rec_list)        
            return float(recall_value/num_instance),rec_list,sorting_indices
        
        def getAUPRC(self):
            avgPrecision,precisions = self.avgPrecision()
            avfRecall,recalls, sorting_indices  = self.avgRecall()
            #x is either increasing or decreasing 
            #such as recalls[sorting_indices] 
            auprc = auc(recalls[sorting_indices], precisions[sorting_indices])
            return auprc
    
        def cal_single_label_micro_auc(self,x, y):
            idx = np.argsort(x)  # 升序排列
            y = y[idx]
            m = 0
            n = 0
            auc = 0
            for i in range(x.shape[0]):
                if y[i] == 1:
                    m += 1
                    auc += n
                if y[i] == 0:
                    n += 1
            auc /= (m * n)
            return auc
    
        def get_micro_auc(self):
            """
            :param x: the predicted outputs of the classifier, the output of the ith instance for the jth class is stored in x(i,j)
            :param y: the actual labels of the instances, if the ith instance belong to the jth class, y(i,j)=1, otherwise y(i,j)=0
            :return: the micro auc
            """
            x =self.output
            y = self.label
            n, d = x.shape
            if x.shape[0] != y.shape[0]:
                print("num of  instances for output and ground truth is different!!")
            if x.shape[1] != y.shape[1]:
                print("dim of  output and ground truth is different!!")
            x = x.reshape(n * d)
            y = y.reshape(n * d)
            auc = self.cal_single_label_micro_auc(x, y)
            return auc
        
        def cal_single_instance_coverage(self,x, y):
            idx = np.argsort(x)  # 升序排列
            y = y[idx]
            loc = x.shape[0]
            for i in range(x.shape[0]):
                if y[i] == 1:
                    loc -= i
                    break
            return loc   
    
        def get_coverage(self):
            """
            :param x: the predicted outputs of the classifier, the output of the ith instance for the jth class is stored in x(i,j)
            :param y: the actual labels of the test instances, if the ith instance belong to the jth class, y(i,j)=1, otherwise y(i,j)=0
            :return: the coverage
            """
            x =self.output
            y = self.label
            n, d = x.shape
            if x.shape[0] != y.shape[0]:
                print("num of  instances for output and ground truth is different!!")
            if x.shape[1] != y.shape[1]:
                print("dim of  output and ground truth is different!!")
            cover = 0
            for i in range(n):
                cover += self.cal_single_instance_coverage(x[i], y[i])
            cover = cover / n - 1
            return cover
        
        def cal_single_instance_ranking_loss(self,x, y):
            idx = np.argsort(x)  # 升序排列
            y = y[idx]
            m = 0
            n = 0
            rl = 0
            for i in range(x.shape[0]):
                if y[i] == 1:
                    m += 1
                if y[i] == 0:
                    rl += m
                    n += 1
            rl /= (m * n)
            return rl
        
    
        def get_ranking_loss(self):
            """
            :param x: the predicted outputs of the classifier, the output of the ith instance for the jth class is stored in x(i,j)
            :param y: the actual labels of the test instances, if the ith instance belong to the jth class, y(i,j)=1, otherwise x(i,j)=0
            :return: the ranking loss
            """
            x =self.output
            y = self.label
            n, d = x.shape
            if x.shape[0] != y.shape[0]:
                print("num of  instances for output and ground truth is different!!")
            if x.shape[1] != y.shape[1]:
                print("dim of  output and ground truth is different!!")
            m = 0
            rank_loss = 0
            for i in range(n):
                s = np.sum(y[i])
                if s in range(1, d):
                    rank_loss += self.cal_single_instance_ranking_loss(x[i], y[i])
                    m += 1
            rank_loss /= m
            return rank_loss    
                         
    if __name__ == '__main__':
        # 6行5列，6个样本，5个类别标记
        output = np.array([[1,0,0,0,1],
                           [1,1,0,1,0],
                           [0,1,0,0,1],
                           [1,0,1,0,1],
                           [1,0,1,1,1],
                           [1,1,0,0,1]
                ])
        
        label = np.array([ [1,0,1,0,1],
                           [1,1,0,1,0],
                           [0,1,0,0,1],
                           [0,1,0,0,1],
                           [0,0,1,0,1],
                           [1,1,0,0,1]
                ])
        myMetic = Metric(output,label)
        #Macrof1 = myMetic.fscore_class()
        ham = myMetic.hamming_distance()
        Microf1 = myMetic.micfscore()
        Macrof1 = myMetic.macfscore() 
        AUROC = myMetic.auROC() 
        MacroAUROC1,AUC_list = myMetic.MacroAUC() 
        avgPrecision,precisions = myMetic.avgPrecision()
        avfRecall,recalls,sorting_indices  = myMetic.avgRecall()
        auprc  = myMetic.getAUPRC()
        #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
        micro_auc = myMetic.get_micro_auc()
        coverage = myMetic.get_coverage()
        ranking_loss = myMetic.get_ranking_loss()
    #    #print(Macrof1)
        print("ham:",ham)
        print("Microf1:",Microf1)   
        print("Macrof1:",Macrof1)
        print("AUROC: ",(AUROC))     
        print("MacroAUC: ",(MacroAUROC1)) 
    #    #print(": ",(AUC_list)) 
        print("avgPrecision: ",avgPrecision) 
        print("avfRecall: ",avfRecall)
        print("AUPRC: ",auprc) 
        print("get_micro_auc _from_KDD2018M3DS:",micro_auc)
        print("get_coverage _from_KDD2018M3DS:",coverage)
        print("get_ranking_loss _from_KDD2018M3DS:",ranking_loss)
    #    #iris = datasets.load_iris()

计算AUPRC参考了该[作者][Link 2]

ps:能力有限，有错误地方，可在下方评论，不定时修改

[Link 1]: https://scikit-learn.org/stable/modules/model_evaluation.html#precision-recall-f-measure-metrics
[Link 2]: https://github.com/sainathadapa/dcase2019-task5-urban-sound-tagging/blob/8e89a7b4f4c96bdaa3a4691cee38c5661f853196/baseline_code/metrics.py