Python深度学习教程:LSTM时间序列预测小练习—国航乘客数量预测
参考数据:
数据一共两列,左边是日期,右边是乘客数量
对数据做可视化:
import math
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
from pandas import read_csv
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
#load dataset
dataframe = read_csv('./international-airline-passengers.csv',usecols =[1],header = None,engine = 'python',skipfooter = 3)
dataset = dataframe.values
#将整型变为float
dataset = dataset.astype('float32')
plt.plot(dataset)
plt.show()
可视化结果:
完整代码:
import math
import numpy
import pandas as pd
import matplotlib.pyplot as plt
from pandas import read_csv
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
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]
b = dataset[i+look_back,0]
dataX.append(a)
dataY.append(b)
return numpy.array(dataX),numpy.array(dataY)
numpy.random.seed(7)
dataframe = read_csv('./international-airline-passengers.csv',usecols = [1],header = None,engine = 'python')
dataset = dataframe.values
dataset = dataset.astype('float32')
scaler = MinMaxScaler(feature_range = (0,1))
dataset = scaler.fit_transform(dataset)
train_size = int(len(dataset) * 0.67)
test_size = len(dataset) - train_size
train,test = dataset[0:train_size,:],dataset[train_size:len(dataset),:]
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],look_back,trainX.shape[1]))
testX = numpy.reshape(testX,(testX.shape[0],look_back,testX.shape[1]))
#create and fit the LSTM network
model = Sequential()
model.add(LSTM(4,input_shape = (1,look_back)))
model.add(Dense(1))
model.compile(loss = 'mean_squared_error',optimizer = 'adam')
model.fit(trainX,trainY,epochs = 100,batch_size = 1,verbose = 2)
# make predictions
trainPredict = model.predict(trainX)
testPredict = model.predict(testX)
# invert predictions
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()
运行结果:
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