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@ranpelta
Created July 18, 2020 08:29
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import pandas as pd
import numpy as np
import keras
import matplotlib.pyplot as plt
from sklearn.preprocessing import MinMaxScaler
from pandas.plotting import register_matplotlib_converters
register_matplotlib_converters()
from keras.preprocessing.sequence import TimeseriesGenerator
from keras.models import Sequential
from keras.layers import Dense
from keras.layers import LSTM
df = pd.read_pickle(r'C:\....\data.pkl') # read data
y_col='y' # define y variable, i.e., what we want to predict
test_size = int(len(df) * 0.1) # here I ask that the test data will be 10% (0.1) of the entire data
train = df.iloc[:-test_size,:].copy() # the copy() here is important, it will prevent us from getting: SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame.
# Try using .loc[row_index,col_indexer] = value instead
test = df.iloc[-test_size:,:].copy()
X_train = train.drop(y_col,axis=1).copy()
y_train = train[[y_col]].copy() # the double brakets here are to keep the y in dataframe format, otherwise it will be pandas Series
Xscaler = MinMaxScaler(feature_range=(0, 1)) # scale so that all the X data will range from 0 to 1
Xscaler.fit(X_train)
scaled_X_train = Xscaler.transform(X_train)
Yscaler = MinMaxScaler(feature_range=(0, 1))
Yscaler.fit(y_train)
scaled_y_train = Yscaler.transform(y_train)
scaled_y_train = scaled_y_train.reshape(-1) # remove the second dimention from y so the shape changes from (n,1) to (n,)
scaled_y_train = np.insert(scaled_y_train, 0, 0)
scaled_y_train = np.delete(scaled_y_train, -1)
n_input = 25 #how many samples/rows/timesteps to look in the past in order to forecast the next sample
n_features= X_train.shape[1] # how many predictors/Xs/features we have to predict y
b_size = 32 # Number of timeseries samples in each batch
generator = TimeseriesGenerator(scaled_X_train, scaled_y_train, length=n_input, batch_size=b_size)
model = Sequential()
model.add(LSTM(150, activation='relu', input_shape=(n_input, n_features)))
model.add(Dense(1))
model.compile(optimizer='adam', loss='mse')
model.fit_generator(generator,epochs=5)
X_test = test.drop(y_col,axis=1).copy()
scaled_X_test = Xscaler.transform(X_test)
test_generator = TimeseriesGenerator(scaled_X_test, np.zeros(len(X_test)), length=n_input, batch_size=b_size)
y_pred_scaled = model.predict(test_generator)
y_pred = Yscaler.inverse_transform(y_pred_scaled)
results = pd.DataFrame({'y_true':test[y_col].values[n_input:],'y_pred':y_pred.ravel()})
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