更加精准的时间序列预测--基于Python的 LSTM模型
数据分析1480
共 7790字,需浏览 16分钟
·
2022-06-09 16:33
什么是时间序列分析? 什么是 LSTM?
单变量时间序列 多元时间序列
import numpy as np
import pandas as pd
from matplotlib import pyplot as plt
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import LSTM
from tensorflow.keras.layers import Dense, Dropout
from sklearn.preprocessing import MinMaxScaler
from keras.wrappers.scikit_learn import KerasRegressor
from sklearn.model_selection import GridSearchCV
df=pd.read_csv("train.csv",parse_dates=["Date"],index_col=[0])
df.head()
df.tail()
df.shape
(5203,5)
test_split=round(len(df)*0.20)
df_for_training=df[:-1041]
df_for_testing=df[-1041:]
print(df_for_training.shape)
print(df_for_testing.shape)
(4162, 5)
(1041, 5)
scaler = MinMaxScaler(feature_range=(0,1))
df_for_training_scaled = scaler.fit_transform(df_for_training)
df_for_testing_scaled=scaler.transform(df_for_testing)
df_for_training_scaled
def createXY(dataset,n_past):
dataX = []
dataY = []
for i in range(n_past, len(dataset)):
dataX.append(dataset[i - n_past:i, 0:dataset.shape[1]])
dataY.append(dataset[i,0])
return np.array(dataX),np.array(dataY)
trainX,trainY=createXY(df_for_training_scaled,30)
testX,testY=createXY(df_for_testing_scaled,30)
data_X.addend (df_for_training_scaled[i - n_past:i, 0:df_for_training.shape[1]])
print("trainX Shape-- ",trainX.shape)
print("trainY Shape-- ",trainY.shape)
(4132, 30, 5)
(4132,)
print("testX Shape-- ",testX.shape)
print("testY Shape-- ",testY.shape)
(1011, 30, 5)
(1011,)
print("trainX[0]-- \n",trainX[0])
print("trainY[0]-- ",trainY[0])
trainX — — →trainY
[0 : 30,0:5] → [30,0]
[1:31, 0:5] → [31,0]
[2:32,0:5] →[32,0]
def build_model(optimizer):
grid_model = Sequential()
grid_model.add(LSTM(50,return_sequences=True,input_shape=(30,5)))
grid_model.add(LSTM(50))
grid_model.add(Dropout(0.2))
grid_model.add(Dense(1))
grid_model.compile(loss = 'mse',optimizer = optimizer)
return grid_modelgrid_model = KerasRegressor(build_fn=build_model,verbose=1,validation_data=(testX,testY))
parameters = {'batch_size' : [16,20],
'epochs' : [8,10],
'optimizer' : ['adam','Adadelta'] }
grid_search = GridSearchCV(estimator = grid_model,
param_grid = parameters,
cv = 2)
(trainX.shape[1],trainX.shape[2]) → (30,5)
grid_search = grid_search.fit(trainX,trainY)
grid_search.best_params_
{‘batch_size’: 20, ‘epochs’: 10, ‘optimizer’: ‘adam’}
my_model=grid_search.best_estimator_.model
prediction=my_model.predict(testX)
print("prediction\n", prediction)
print("\nPrediction Shape-",prediction.shape)
scaler.inverse_transform(prediction)
prediction_copies_array = np.repeat(prediction,5, axis=-1)
prediction_copies_array.shape
(1011,5)
pred=scaler.inverse_transform(np.reshape(prediction_copies_array,(len(prediction),5)))[:,0]
original_copies_array = np.repeat(testY,5, axis=-1)
original=scaler.inverse_transform(np.reshape(original_copies_array,(len(testY),5)))[:,0]
print("Pred Values-- " ,pred)
print("\nOriginal Values-- " ,original)
plt.plot(original, color = 'red', label = 'Real Stock Price')
plt.plot(pred, color = 'blue', label = 'Predicted Stock Price')
plt.title('Stock Price Prediction')
plt.xlabel('Time')
plt.ylabel('Google Stock Price')
plt.legend()
plt.show()
df_30_days_past=df.iloc[-30:,:]
df_30_days_past.tail()
df_30_days_future=pd.read_csv("test.csv",parse_dates=["Date"],index_col=[0])
df_30_days_future
df_30_days_future["Open"]=0
df_30_days_future=df_30_days_future[["Open","High","Low","Close","Adj Close"]]
old_scaled_array=scaler.transform(df_30_days_past)
new_scaled_array=scaler.transform(df_30_days_future)
new_scaled_df=pd.DataFrame(new_scaled_array)
new_scaled_df.iloc[:,0]=np.nan
full_df=pd.concat([pd.DataFrame(old_scaled_array),new_scaled_df]).reset_index().drop(["index"],axis=1)
full_df_scaled_array=full_df.values
all_data=[]
time_step=30
for i in range(time_step,len(full_df_scaled_array)):
data_x=[]
data_x.append(
i , 0:full_df_scaled_array.shape[1]]) :
data_x=np.array(data_x)
prediction=my_model.predict(data_x)
all_data.append(prediction)
prediction =
new_array=np.array(all_data)
new_array=new_array.reshape(-1,1)
prediction_copies_array = np.repeat(new_array,5, axis=-1)
y_pred_future_30_days = scaler.inverse_transform(np.reshape(prediction_copies_array,(len(new_array),5)))[:,0]
print(y_pred_future_30_days)
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