LSTM-Keras错误:ValueError: 输出操作数的形状(67704,1)不可广播,与广播形状(67704,12)不匹配。

10

大家早上好。我正在尝试使用Keras和pandas实现这个LSTM算法,以读取csv文件。我使用的后端是Tensorflow。当我需要在预测训练集之前反转结果时,我遇到了问题。以下是我的代码:

import numpy
import matplotlib.pyplot as plt
import pandas
import math
from keras.models import Sequential
from keras.layers import Dense
from keras.layers import LSTM
from sklearn.preprocessing import MinMaxScaler
from sklearn.metrics import mean_squared_error


#plt.plot(dataset)
#plt.show()

#fix random seed for reproducibility
numpy.random.seed(7)

#Load dataset
col_names = ['UserID','SysTouchTime', 'EventTime', 'ActivityTouchID', 'Pointer_count', 'PointerID',
                'ActionID', 'Touch_X', 'Touch_Y', 'Touch_Pressure', 'Contact_Size', 'Phone_Orientation']
dataframe = pandas.read_csv('touchEventsFor5Users.csv', engine='python', header=None, names = col_names, skiprows=1)
#print(dataset.head())
#print(dataset.shape)
dataset = dataframe.values
dataset = dataframe.astype('float32')
print(dataset.isnull().any())
dataset = dataset.fillna(method='ffill')
feature_cols = ['SysTouchTime', 'EventTime', 'ActivityTouchID', 'Pointer_count', 'PointerID', 'ActionID', 'Touch_X', 'Touch_Y', 'Touch_Pressure', 'Contact_Size', 'Phone_Orientation']

X = dataset[feature_cols]
y = dataset['UserID']
print(y.head())
#normalize the dataset
scaler = MinMaxScaler(feature_range=(0, 1))
dataset = scaler.fit_transform(dataset)

# split into train and test sets

train_size = int(len(dataset) * 0.67)
test_size = len(dataset) - train_size
train, test = dataset[0:train_size, :], dataset[train_size:len(dataset),:]
print(len(train), len(test))

# convert an array of values into a dataset matrix
def create_dataset(dataset, look_back=1):
    dataX, dataY = [], []
    for i in range(len(dataset)-look_back-1):
        a = dataset[i:(i+look_back), 0]
        dataX.append(a)
        dataY.append(dataset[i + look_back, 0])
    return numpy.array(dataX), numpy.array(dataY)

# reshape into X=t and Y=t+1
look_back = 1
trainX, trainY = create_dataset(train, look_back)
testX, testY = create_dataset(test, look_back)

#reshape input to be [samples, time steps, features]
trainX = numpy.reshape(trainX, (trainX.shape[0], 1, trainX.shape[1]))
testX = numpy.reshape(testX, (testX.shape[0], 1, testX.shape[1]))

#create and fit the LSTM network
model = Sequential()
model.add(LSTM(4, input_dim=look_back))
model.add(Dense(1))
model.compile(loss='mean_squared_error', optimizer='adam', metrics=['accuracy'])
model.fit(trainX, trainY, epochs=1, batch_size=32, verbose=2)

# make predictions
trainPredict = model.predict(trainX)
testPredict = model.predict(testX)
# invert predictions
import gc
gc.collect()

#####problem occurs with the following line of code#############

trainPredict = scaler.inverse_transform(trainPredict)

trainY = scaler.inverse_transform([trainY])
testPredict = scaler.inverse_transform(testPredict)
testY = scaler.inverse_transform([testY])
# calculate root mean squared error
trainScore = math.sqrt(mean_squared_error(trainY[0], trainPredict[:,0]))
print('Train Score: %.2f RMSE' % (trainScore))
testScore = math.sqrt(mean_squared_error(testY[0], testPredict[:,0]))
print('Test Score: %.2f RMSE' % (testScore))

#shift train predictions for plotting
trainPredictPlot = numpy.empty_like(dataset)
trainPredictPlot[:, :] = numpy.nan
trainPredictPlot[look_back:len(trainPredict)+look_back, :] = trainPredict
# shift test predictions for plotting
testPredictPlot = numpy.empty_like(dataset)
testPredictPlot[:, :] = numpy.nan
testPredictPlot[len(trainPredict)+(look_back*2)+1:len(dataset)-1, :] = testPredict
# plot baseline and predictions
plt.plot(scaler.inverse_transform(dataset))
plt.plot(trainPredictPlot)
plt.plot(testPredictPlot)
plt.show()

我遇到的错误是:
ValueError: 输出操作数的形状 (67704,1) 无法广播到与广播形状 (67704,12) 相匹配。
你们能帮我解决这个问题吗?虽然我很新手,但我非常想学习它,而这个错误让我很苦恼!感谢您所提供的任何帮助。
2个回答

17
当您对数据进行缩放时,它会以不同的比例缩放这12个字段。它将获取每个字段的最小值和最大值,并将其转换为0到1之间的值。
当您进行反向转换时,因为您只提供了一个字段,所以该函数没有意义,它不知道如何处理它,它的最小值和最大值是什么... 您需要提供一个包含12个字段的数据集,并在正确位置放置预测字段。
在出现问题的行之前尝试添加以下内容:
# create empty table with 12 fields
trainPredict_dataset_like = np.zeros(shape=(len(train_predict), 12) )
# put the predicted values in the right field
trainPredict_dataset_like[:,0] = trainPredict[:,0]
# inverse transform and then select the right field
trainPredict = scaler.inverse_transform(trainPredict_dataset_like)[:,0]

这个有帮助吗?:)


Edited again :) - Nassim Ben
1
收到了一个弃用警告(我讨厌这些东西),并出现了以下错误: ValueError: 无法将形状为 (67704,)、(12,) 和 (67704,) 的操作数进行广播。 - Jamiel
错误出现在哪一行?能否在每行之后打印形状? - Nassim Ben
非常感谢。这是形状:(67704,12) - Jamiel
trainPredict = scaler.inverse_transform(trainPredict_dataset_like)[:,0]trainPredict = scaler.inverse_transform(trainPredict) 之间。 - Jamiel
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0
x_df = pd.DataFrame(prepared, None, [
    'open',
    '..',
])

# Scale
# ------------------------------------------------------------------------

scaler = MinMaxScaler()
scaled = scaler.fit_transform(x_df)

x_df_scaled = pd.DataFrame(scaled, None, x_df.keys())
x_df_scaled_expanded = np.expand_dims(x_df_scaled, axis=0)

# Model
# ------------------------------------------------------------------------

model = tf.keras.models.load_model(filepath_model)
y = model.predict(x_df_scaled_expanded)

# Scale back
# ------------------------------------------------------------------------

y_df = pd.DataFrame(np.zeros((len(x_df), len(x_df.columns))), columns=x_df.columns)
y_df['open'] = y[0][:, 0]

y_inversed = scaler.inverse_transform(y_df)

y_df['open'] = y_inversed[:, 0]

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