我想根据y_test和pred_test得到一个混淆矩阵，但是提出了一个问题“At least one label specified must be in y_true”，我不知道为什么
metrics.confusion_matrix(np.argmax(y_test,axis=1),pred_test)
y_test = [[0. 1. 0. 0. 0. 0.]
[0. 0. 0. 0. 0. 1.]
[0. 0. 0. 0. 1. 0.]
...
[0. 0. 0. 1. 0. 0.]
[0. 0. 1. 0. 0. 0.]
[0. 0. 1. 0. 0. 0.]]
pred_test = [1 4 5 ... 3 2 2]
np.argmax(y_test,axis=1) = [1 5 4 ... 3 2 2]
File "D:\Anaconda\lib\site-packages\sklearn\metrics\classification.py", line 259, in confusion_matrix
raise ValueError("At least one label specified must be in y_true")
ValueError: At least one label specified must be in y_true
我创建了一个卷积神经网络。模型并使用交叉验证进行估计，最终生成混淆矩阵。现在生成混淆矩阵有问题。
数据集是enter link description here .完整代码如下:
import matplotlib
#matplotlib.use('Agg')
import timing
from keras.layers import Input,Dense,Conv2D,MaxPooling2D,UpSampling2D,Flatten
from keras.models import Model
from keras import backend as K
from keras.utils.np_utils import to_categorical
import numpy as np
import pandas as pd
import seaborn as sns
from keras.models import Sequential# 导入Sequential
from keras.utils import np_utils, generic_utils
from keras.callbacks import LearningRateScheduler
import os
from keras.layers import Dropout
from keras.backend.tensorflow_backend import set_session
import tensorflow as tf
from sklearn.model_selection import train_test_split, cross_val_score
from sklearn.cross_validation import KFold, StratifiedKFold
from keras.wrappers.scikit_learn import KerasClassifier
from sklearn.preprocessing import LabelEncoder
from sklearn import metrics
import time
from scipy import stats
from keras import optimizers
import matplotlib.pyplot as plt
from keras import regularizers
import keras
from keras.callbacks import TensorBoard
config = tf.ConfigProto(allow_soft_placement=True)
gpu_options = tf.GPUOptions(per_process_gpu_memory_fraction=0.9)
config.gpu_options.allow_growth = True
sess = tf.Session(config=config)
os.environ['TF_CPP_MIN_LOG_LEVEL']='2'
time1 = time.time()
class LossHistory(keras.callbacks.Callback):
def on_train_begin(self, logs={}):
self.losses = {'batch':[], 'epoch':[]}
self.accuracy = {'batch':[], 'epoch':[]}
self.val_loss = {'batch':[], 'epoch':[]}
self.val_acc = {'batch':[], 'epoch':[]}
def on_batch_end(self, batch, logs={}):
self.losses['batch'].append(logs.get('loss'))
self.accuracy['batch'].append(logs.get('acc'))
self.val_loss['batch'].append(logs.get('val_loss'))
self.val_acc['batch'].append(logs.get('val_acc'))
def on_epoch_end(self, batch, logs={}):
self.losses['epoch'].append(logs.get('loss'))
self.accuracy['epoch'].append(logs.get('acc'))
self.val_loss['epoch'].append(logs.get('val_loss'))
self.val_acc['epoch'].append(logs.get('val_acc'))
def loss_plot(self, loss_type):
iters = range(len(self.losses[loss_type]))
plt.figure()
# acc
plt.plot(iters, self.accuracy[loss_type], 'r', label='train acc')
# loss
plt.plot(iters, self.losses[loss_type], 'g', label='train loss')
if loss_type == 'epoch':
# val_acc
plt.plot(iters, self.val_acc[loss_type], 'b', label='val acc')
# val_loss
plt.plot(iters, self.val_loss[loss_type], 'k', label='val loss')
plt.grid(True)
plt.xlabel(loss_type)
plt.ylabel('acc-loss')
plt.legend(loc="center")
plt.show()
#plt.savefig('common.png')
#dataset
RANDOM_SEED = 42
def read_data(file_path):
column_names = ['user-id', 'activity', 'timestamp', 'x-axis', 'y-axis', 'z-axis']
m = pd.read_csv(file_path,names=column_names, header=None,sep=',')
return m
def feature_normalize(dataset):
mu = np.mean(dataset,axis=0)
sigma = np.std(dataset,axis=0)
return (dataset-mu)/sigma
dataset1 = read_data('ab.txt')
dataset = pd.DataFrame(dataset1)
dataset['x-axis'] = feature_normalize(dataset['x-axis'])
dataset['y-axis'] = feature_normalize(dataset['y-axis'])
dataset['z-axis'] = feature_normalize(dataset['z-axis'])
N_TIME_STEPS = 200
N_FEATURES = 3
step = 200
segments = []
labels = []
for i in range(0, len(dataset) - N_TIME_STEPS, step):
xs = dataset['x-axis'].values[i: i + N_TIME_STEPS]
ys = dataset['y-axis'].values[i: i + N_TIME_STEPS]
zs = dataset['z-axis'].values[i: i + N_TIME_STEPS]
label = stats.mode(dataset['activity'][i: i + N_TIME_STEPS])[0][0]
segments.append([xs, ys, zs])
labels.append(label)
print("reduced size of data", np.array(segments).shape)
reshaped_segments = np.asarray(segments,dtype=np.float32).reshape(-1,1, N_TIME_STEPS, 3)
print("Reshape the segments", np.array(reshaped_segments).shape)
#x_train1, x_val_test, y_train1, y_val_test = train_test_split(reshaped_segments, labels, test_size=0.25, random_state=RANDOM_SEED)
batch_size = 128
num_classes =6
def create_model():
input_shape = Input(shape=(1,200,3))
x = Conv2D(5, kernel_size=(1, 1), padding='valid')(input_shape)
x1 = keras.layers.concatenate([input_shape, x], axis=-1)
x = Conv2D(50, kernel_size=(1, 7),padding='valid',
kernel_initializer='glorot_uniform',
kernel_regularizer = keras.regularizers.l2(0.0015))(x1)
x = keras.layers.core.Activation('relu')(x)
x = MaxPooling2D(pool_size=(1, 2))(x)
x = Conv2D(50, kernel_size=(1, 7),padding='valid',kernel_initializer='glorot_uniform',
kernel_regularizer=keras.regularizers.l2(0.0015))(x)
x = keras.layers.core.Activation('relu')(x)
x = MaxPooling2D(pool_size=(1, 2))(x)
x = Flatten()(x)
x = Dropout(0.9)(x)
output = Dense(num_classes, activation='softmax',kernel_initializer='glorot_uniform',)(x)
model = Model(inputs=input_shape,outputs=output)
model.summary()
sgd = optimizers.SGD(lr=0.005,decay=1e-6,momentum=0.9,nesterov=True)
model.compile(loss=keras.losses.categorical_crossentropy,
optimizer=sgd,
metrics=['accuracy'])
return model
history = LossHistory()
epochs = 4000
#setting learning rate
def scheduler(epoch):
if epoch > 0.75 * epochs:
lr = 0.0005
elif epoch > 0.25 * epochs:
lr = 0.001
else:
lr = 0.005
return lr
scheduler = LearningRateScheduler(scheduler)
estimator = KerasClassifier(build_fn=create_model)
#divide dataset
scores = []
confusions = []
sign = ['DOWNSTAIRS','JOGGING','SITTING','STANDING','UPSTAIRS','WALKING']
encoder = LabelEncoder()
encoder_y = encoder.fit_transform(labels)
train_labels = to_categorical(encoder_y,num_classes=None)
#kfold = StratifiedKFold(reshaped_segments.shape[0],n_folds=10,shuffle=True,random_state=42)
kfold = StratifiedKFold(labels,n_folds=3,shuffle=True,random_state=42)
for train_index,test_index in kfold:
print(test_index)
x_train, x_test = reshaped_segments[train_index], reshaped_segments[test_index]
y_train, y_test = train_labels[train_index], train_labels[test_index]
estimator.fit(x_train,y_train,callbacks=[scheduler,history],epochs=10,batch_size=128,verbose=0)
scores.append(estimator.score(x_test,y_test))
print(y_test)
print(type(y_test))
pred_test = estimator.predict(x_test)
print(pred_test)
print(np.argmax(y_test,axis=1))
confusions.append(metrics.confusion_matrix(np.argmax(y_test,axis=1),pred_test,sign))
matrix = [[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0],[0,0,0,0,0,0]]
for i in np.arange(n_folds-1):
for j in len(confusions[0]):
for k in len(confusions[0][0]):
matrix[j][k] = matrix[j][k] + confusions[i][j][k] + confusions[i+1][j][k]
model.save('model.h5')
model.save_weights('my_model_weights.h5')
print('score:',scores)
scores = np.mean(scores)
print('mean:',scores)
plt.figure(figsize=(16,14))
sns.heatmap(matrix, xticklabels=sign, yticklabels=sign, annot=True, fmt="d");
plt.title("CONFUSION MATRIX : ")
plt.ylabel('True Label')
plt.xlabel('Predicted label')
plt.savefig('cmatrix.png')
plt.show();
最佳答案
错误不在您的主代码中，而是在符号的定义中。当您将符号定义为
sign = ['DOWNSTAIRS','JOGGING','SITTING','STANDING','UPSTAIRS','WALKING']
系统无法读取您的标签，因为它正在寻找标签 0、1、2、3、4、5 作为错误试图说明的内容，即它在 y_pred 中找不到任何标签。 更改符号为
sign = [1,2,3,4,5]
应该修复错误。至于你现在做什么，它相当简单，只需将你的结果映射为这个数组，然后在实际预测(部署)期间，只需换出标签的数值。
关于python - 至少指定一个标签必须在 y_true 中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52250821/