Python spyder + tensorflow cross validation freezes on Windows 10 - windows

Question

On Windows 10, I have installed Anaconda and launched Spyder. I have also successfully installed Theano, Tensorflow and Keras, since when I execute
import keras
the console outputs
Using Tensorflow Backend
When I compile and fit the neural network it runs fine. But when I try to run k-fold cross validation, combining the scikit-learn via a keras wrapper and using the parameter n_jobs = -1 (and generally n_jobs with whatever value, thus having multiprocessing), the console just freezes forever until restarting kernel manually or terminating Spyder.
Another problem, when I try to run some parameter tuning using GridSearchCV, for i.e. 100 epochs, it doesn't freeze but it outputs epoch 1/1 instead of 1/100 and generally it gives bad results, not logical (i.e. it runs only for a couple of minutes, while normally it would take hours!).
My code is:
# Part 1 - Data Preprocessing
# Importing the libraries
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
# Importing the dataset
dataset = pd.read_csv('Churn_Modelling.csv')
X = dataset.iloc[:, 3:13].values
y = dataset.iloc[:, 13].values
# Encoding categorical data
# Encoding the Independent Variable
from sklearn.preprocessing import LabelEncoder, OneHotEncoder
labelencoder_X_1 = LabelEncoder()
X[:, 1] = labelencoder_X_1.fit_transform(X[:, 1])
labelencoder_X_2 = LabelEncoder()
X[:, 2] = labelencoder_X_2.fit_transform(X[:, 2])
onehotencoder = OneHotEncoder(categorical_features = [1])
X = onehotencoder.fit_transform(X).toarray()
# Avoiding the dummy variable trap
X = X[:, 1:]
# Splitting the dataset into the Training set and Test set
from sklearn.cross_validation import train_test_split
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size = 0.2, random_state = 0)
# Feature Scaling
from sklearn.preprocessing import StandardScaler
sc = StandardScaler()
X_train = sc.fit_transform(X_train)
X_test = sc.transform(X_test)
# Part 2 - Now let's make the ANN!
# Importing the Keras libraries and packages
import keras
from keras.models import Sequential
from keras.layers import Dense
from keras.layers import Dropout
# Initialising the ANN
classifier = Sequential()
# Adding the input layer and the first hidden layer with dropout
classifier.add(Dense(units = 6, kernel_initializer = 'uniform', activation = 'relu', input_dim = 11))
classifier.add(Dropout(rate = 0.1)) # p should vary from 0.1 to 0.4, NOT HIGHER, because then we will have under-fitting.
# Adding the second hidden layer with dropout
classifier.add(Dense(units = 6, kernel_initializer = 'uniform', activation = 'relu'))
classifier.add(Dropout(rate = 0.1))
# Adding the output layer
classifier.add(Dense(units = 1, kernel_initializer = 'uniform', activation = 'sigmoid'))
# Compiling the ANN
classifier.compile(optimizer = 'adam', loss = 'binary_crossentropy', metrics = ['accuracy'])
# Fitting the ANN to the Training set
classifier.fit(X_train, y_train, batch_size = 10, epochs = 100)
# Part 3 - Making predictions and evaluating the model
# Predicting the Test set results
y_pred = classifier.predict(X_test)
y_pred = (y_pred > 0.5)
# Making the Confusion Matrix
from sklearn.metrics import confusion_matrix
cm = confusion_matrix(y_test, y_pred)
new_prediction = classifier.predict(sc.transform(np.array([[0, 0, 600, 1, 40, 3, 60000, 2, 1, 1, 50000]])))
new_prediction = (new_prediction > 0.5)
#Part 4 = Evaluating, Improving and Tuning the ANN
# Evaluating the ANN
from keras.wrappers.scikit_learn import KerasClassifier
from sklearn.model_selection import cross_val_score
from keras.models import Sequential
from keras.layers import Dense
def build_classifier():
classifier = Sequential()
classifier.add(Dense(units = 6, kernel_initializer = 'uniform', activation = 'relu', input_dim = 11))
classifier.add(Dense(units = 6, kernel_initializer = 'uniform', activation = 'relu'))
classifier.add(Dense(units = 1, kernel_initializer = 'uniform', activation = 'sigmoid'))
classifier.compile(optimizer = 'adam', loss = 'binary_crossentropy', metrics = ['accuracy'])
return classifier
classifier = KerasClassifier(build_fn = build_classifier, batch_size = 10, nb_epoch = 100)
accuracies = cross_val_score(estimator = classifier, X = X_train, y = y_train, cv = 10, n_jobs = -1)
mean = accuracies.mean()
variance = accuracies.std()
# Improving the ANN
# Tuning the ANN
from keras.wrappers.scikit_learn import KerasClassifier
from sklearn.model_selection import GridSearchCV
from keras.models import Sequential
from keras.layers import Dense
def build_classifier(optimizer):
classifier = Sequential()
classifier.add(Dense(units = 6, kernel_initializer = 'uniform', activation = 'relu', input_dim = 11))
classifier.add(Dense(units = 6, kernel_initializer = 'uniform', activation = 'relu'))
classifier.add(Dense(units = 1, kernel_initializer = 'uniform', activation = 'sigmoid'))
classifier.compile(optimizer = optimizer, loss = 'binary_crossentropy', metrics = ['accuracy'])
return classifier
classifier = KerasClassifier(build_fn = build_classifier)
parameters = {"batch_size": [25, 32],
"nb_epoch": [100, 500],
"optimizer": ["adam", "rmsprop"]}
grid_search = GridSearchCV(estimator = classifier,
param_grid = parameters,
scoring = "accuracy",
cv = 10)
grid_search = grid_search.fit(X_train, y_train)
best_parameters = grid_search.best_params_
best_accuracy = grid_search.best_score_
Also, for n_jobs = 1, it runs but says epoch 1/1 and runs 10 times, which is the k-fold value. That means that it recognizes nb_epoch = 1 and not 100 for some reason.
Finally, I tried enclosing the cross_val_score() into a class:
class run():
def __init__(self):
cross_val_score(estimator = classifier, X = X_train, y = y_train, cv = 10, n_jobs = -1)
if __name__ == '__main__':
run()
or have it only with the if condition:
if __name__ == '__main__':
cross_val_score(estimator = classifier, X = X_train, y = y_train, cv = 10, n_jobs = -1)
but it doesn't work either, it freezes again.
Can anyone help me out solving these issues? What is going on, what can I do to solve these so everything runs properly?
Thank you in advance.

Answer 1

it seems Windows has an issue with "n_jobs", remove it in your "accuracies=" code and it will work, downside is it may take a while but at least it will work.