分类指标无法处理连续多输出和多标签指标目标的混合

Question

我创建了一个具有数字输入和单个分类输出的人工神经网络，该输出是一个热编码为 19 个类别中的一个。我将输出层设置为 19 个单位。我现在不知道如何执行混淆矩阵，也不知道如何根据这个而不是单个二进制输出来分类器.predict()。我不断收到错误消息，说分类指标无法处理连续多输出和多标签指标目标的混合。不知道如何继续。

#Importing Datasets
dataset=pd.read_csv('Data.csv')
x = dataset.iloc[:,1:36].values # lower bound independent variable to upper bound in a matrix (in this case only 1 column 'NC')
y = dataset.iloc[:,36:].values # dependent variable vector
print(x.shape)
print(y.shape)

#One Hot Encoding fuel rail column
from sklearn.preprocessing import LabelEncoder, OneHotEncoder
labelencoder_y= LabelEncoder()
y[:,0]=labelencoder_y.fit_transform(y[:,0])
onehotencoder= OneHotEncoder(categorical_features=[0])
y = onehotencoder.fit_transform(y).toarray()
print(y[:,0:])

print(x.shape)
print (y.shape)


#splitting data into Training and Test Data
from sklearn.model_selection import train_test_split
x_train, x_test, y_train, y_test = train_test_split(x,y,test_size=0.1,random_state=0)

#Feature Scaling
from sklearn.preprocessing import StandardScaler
sc = StandardScaler()
#x_train = sc.fit_transform(x_train)
#x_test=sc.transform(x_test)
y_train = sc.fit_transform(y_train)
y_test=sc.transform(y_test)

# PART2 - Making ANN, deep neural network

#Importing the Keras libraries and packages
import keras
from keras.models import Sequential
from keras.layers import Dense


#Initialising ANN
classifier = Sequential()
#Adding the input layer and first hidden layer
classifier.add(Dense(activation= 'relu', input_dim =35, units=2, kernel_initializer="uniform"))#rectifier activation function, include all input with one hot encoding
#Adding second hidden layer
classifier.add(Dense(activation= 'relu', units=2, kernel_initializer="uniform")) #rectifier activation function
#Adding the Output Layer
classifier.add(Dense(activation='softmax', units=19, kernel_initializer="uniform")) 
#Compiling ANN - stochastic gradient descent
classifier.compile(optimizer='adam', loss='categorical_crossentropy', metrics=['accuracy'])#stochastic gradient descent

#Fit ANN to training set

#PART 3 - Making predictions and evaluating the model
#Fitting classifier to the training set
classifier.fit(x_train, y_train, batch_size=10, epochs=100)#original batch is 10 and epoch is 100

#Predicting the Test set rules
y_pred = classifier.predict(x_test)
y_pred = (y_pred > 0.5) #greater than 0.50 on scale 0 to 1
print(y_pred)

#Making confusion matrix that checks accuracy of the model
from sklearn.metrics import confusion_matrix
cm = confusion_matrix(y_test, y_pred)

Answer 1

y_pred = (y_pred > 0.5) 

输出一个布尔矩阵。问题是它的形状和以前一样，但是当你评估准确性时，你需要一个标签向量。

为此，请使用np.argmax(y_pred, axis=1) 来输出正确的标签。

Answer 2

总结一下：使用这段代码，你应该得到你的矩阵

y_pred=model.predict(X_test) 
y_pred=np.argmax(y_pred, axis=1)
y_test=np.argmax(y_test, axis=1)
cm = confusion_matrix(y_test, y_pred)
print(cm)