In [1]:
import os
from sklearn.tree import DecisionTreeClassifier, export_graphviz
import pandas as pd
import numpy as np
from sklearn.cross_validation import train_test_split
from sklearn import cross_validation, metrics
from sklearn.ensemble import RandomForestClassifier
from sklearn.naive_bayes import BernoulliNB
from sklearn.neighbors import KNeighborsClassifier
from sklearn.svm import SVC
from time import time
from sklearn import preprocessing
from sklearn.pipeline import Pipeline
from sklearn.metrics import roc_auc_score , classification_report
from sklearn.grid_search import GridSearchCV
from sklearn.pipeline import Pipeline
from sklearn.metrics import precision_score, recall_score, accuracy_score, classification_report
In [22]:
index=[]
board = ['a','b','c','d','e','f','g']
for i in board:
for j in range(6):
index.append(i + str(j+1))
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column_names = index +['Class']
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# read .csv from provided dataset
csv_filename="connect-4.data"
# df=pd.read_csv(csv_filename,index_col=0)
df=pd.read_csv(csv_filename,
names= column_names)
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df.head()
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df['Class'].unique()
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#Convert animal labels to numbers
le = preprocessing.LabelEncoder()
for col in df.columns:
df[col] = le.fit_transform(df[col])
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df.head()
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for col in df.columns:
df[col] = pd.get_dummies(df[col])
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df.head()
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X = df[index]
y = df['Class']
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X.head()
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In [37]:
# split dataset to 60% training and 40% testing
X_train, X_test, y_train, y_test = cross_validation.train_test_split(X, y, test_size=0.4, random_state=0)
In [38]:
print X_train.shape, y_train.shape
Feature importances with forests of trees¶
This examples shows the use of forests of trees to evaluate the importance of features on an artificial classification task. The red bars are the feature importances of the forest, along with their inter-trees variability.
In [25]:
%matplotlib inline
import numpy as np
import matplotlib.pyplot as plt
from sklearn.ensemble import ExtraTreesClassifier
# Build a classification task using 3 informative features
# Build a forest and compute the feature importances
forest = ExtraTreesClassifier(n_estimators=250,
random_state=0)
forest.fit(X, y)
importances = forest.feature_importances_
std = np.std([tree.feature_importances_ for tree in forest.estimators_],
axis=0)
indices = np.argsort(importances)[::-1]
# Print the feature ranking
print("Feature ranking:")
for f in range(X.shape[1]):
print("%d. feature %d - %s (%f) " % (f + 1, indices[f], features[indices[f]], importances[indices[f]]))
# Plot the feature importances of the forest
plt.figure(num=None, figsize=(14, 10), dpi=80, facecolor='w', edgecolor='k')
plt.title("Feature importances")
plt.bar(range(X.shape[1]), importances[indices],
color="r", yerr=std[indices], align="center")
plt.xticks(range(X.shape[1]), indices)
plt.xlim([-1, X.shape[1]])
plt.show()
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importances[indices[:5]]
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for f in range(5):
print("%d. feature %d - %s (%f)" % (f + 1, indices[f], features[indices[f]] ,importances[indices[f]]))
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best_features = []
for i in indices[:5]:
best_features.append(features[i])
In [29]:
# Plot the top 5 feature importances of the forest
plt.figure(num=None, figsize=(8, 6), dpi=80, facecolor='w', edgecolor='k')
plt.title("Feature importances")
plt.bar(range(5), importances[indices][:5],
color="r", yerr=std[indices][:5], align="center")
plt.xticks(range(5), best_features)
plt.xlim([-1, 5])
plt.show()
Decision Tree accuracy and time elapsed caculation¶
In [39]:
t0=time()
print "DecisionTree"
dt = DecisionTreeClassifier(min_samples_split=20,random_state=99)
# dt = DecisionTreeClassifier(min_samples_split=20,max_depth=5,random_state=99)
clf_dt=dt.fit(X_train,y_train)
print "Acurracy: ", clf_dt.score(X_test,y_test)
t1=time()
print "time elapsed: ", t1-t0
cross validation for DT¶
In [41]:
tt0=time()
print "cross result========"
scores = cross_validation.cross_val_score(dt, X, y, cv=5)
print scores
print scores.mean()
tt1=time()
print "time elapsed: ", tt1-tt0
print "\n"
Tuning our hyperparameters using GridSearch¶
In [42]:
from sklearn.metrics import classification_report
pipeline = Pipeline([
('clf', DecisionTreeClassifier(criterion='entropy'))
])
parameters = {
'clf__max_depth': (5, 25 , 50),
'clf__min_samples_split': (1, 5, 10),
'clf__min_samples_leaf': (1, 2, 3)
}
grid_search = GridSearchCV(pipeline, parameters, n_jobs=-1, verbose=1, scoring='f1')
grid_search.fit(X_train, y_train)
print 'Best score: %0.3f' % grid_search.best_score_
print 'Best parameters set:'
best_parameters = grid_search.best_estimator_.get_params()
for param_name in sorted(parameters.keys()):
print '\t%s: %r' % (param_name, best_parameters[param_name])
predictions = grid_search.predict(X_test)
print classification_report(y_test, predictions)
Exporting Decision Tree to an Image¶
In [43]:
t0=time()
print "DecisionTree"
dt1 = DecisionTreeClassifier(min_samples_split=1,max_depth=25,min_samples_leaf=1, random_state=99)
clf_dt1=dt1.fit(X_train,y_train)
print "Acurracy: ", clf_dt1.score(X_test,y_test)
t1=time()
print "time elapsed: ", t1-t0
export_graphviz(clf_dt1,
out_file='tree.dot',
feature_names=features)
After we have installed GraphViz on our computer, we can convert the tree.dot file into a PNG file by executing the following command from the command line in the location where we saved the tree.dot file:
dot -Tpng tree.dot -o tree.png
Random Forest accuracy and time elapsed caculation¶
In [44]:
t2=time()
print "RandomForest"
rf = RandomForestClassifier(n_estimators=100,n_jobs=-1)
clf_rf = rf.fit(X_train,y_train)
print "Acurracy: ", clf_rf.score(X_test,y_test)
t3=time()
print "time elapsed: ", t3-t2
cross validation for RF¶
In [46]:
tt2=time()
print "cross result========"
scores = cross_validation.cross_val_score(rf, X, y, cv=5)
print scores
print scores.mean()
tt3=time()
print "time elapsed: ", tt3-tt2
print "\n"
Tuning Models using GridSearch¶
In [48]:
pipeline2 = Pipeline([
('clf', RandomForestClassifier(criterion='entropy'))
])
parameters = {
'clf__n_estimators': (5, 25, 50, 100),
'clf__max_depth': (5, 25 , 50),
'clf__min_samples_split': (1, 5, 10),
'clf__min_samples_leaf': (1, 2, 3)
}
grid_search = GridSearchCV(pipeline2, parameters, n_jobs=-1, verbose=1, scoring='accuracy', cv=3)
grid_search.fit(X_train, y_train)
print 'Best score: %0.3f' % grid_search.best_score_
print 'Best parameters set:'
best_parameters = grid_search.best_estimator_.get_params()
for param_name in sorted(parameters.keys()):
print '\t%s: %r' % (param_name, best_parameters[param_name])
predictions = grid_search.predict(X_test)
print 'Accuracy:', accuracy_score(y_test, predictions)
print classification_report(y_test, predictions)
Naive Bayes accuracy and time elapsed caculation¶
In [47]:
t4=time()
print "NaiveBayes"
nb = BernoulliNB()
clf_nb=nb.fit(X_train,y_train)
print "Acurracy: ", clf_nb.score(X_test,y_test)
t5=time()
print "time elapsed: ", t5-t4
cross-validation for NB¶
In [48]:
tt4=time()
print "cross result========"
scores = cross_validation.cross_val_score(nb, X,y, cv=3)
print scores
print scores.mean()
tt5=time()
print "time elapsed: ", tt5-tt4
print "\n"
KNN accuracy and time elapsed caculation¶
In [49]:
t6=time()
print "KNN"
# knn = KNeighborsClassifier(n_neighbors=3)
knn = KNeighborsClassifier(n_neighbors=3)
clf_knn=knn.fit(X_train, y_train)
print "Acurracy: ", clf_knn.score(X_test,y_test)
t7=time()
print "time elapsed: ", t7-t6
cross validation for KNN¶
In [50]:
tt6=time()
print "cross result========"
scores = cross_validation.cross_val_score(knn, X,y, cv=5)
print scores
print scores.mean()
tt7=time()
print "time elapsed: ", tt7-tt6
print "\n"
Fine tuning the model using GridSearch¶
In [92]:
from sklearn.svm import SVC
from sklearn.cross_validation import cross_val_score
from sklearn.pipeline import Pipeline
from sklearn import grid_search
knn = KNeighborsClassifier()
parameters = {'n_neighbors':[1,10]}
grid = grid_search.GridSearchCV(knn, parameters, n_jobs=-1, verbose=1, scoring='accuracy')
grid.fit(X_train, y_train)
print 'Best score: %0.3f' % grid.best_score_
print 'Best parameters set:'
best_parameters = grid.best_estimator_.get_params()
for param_name in sorted(parameters.keys()):
print '\t%s: %r' % (param_name, best_parameters[param_name])
predictions = grid.predict(X_test)
print classification_report(y_test, predictions)
SVM accuracy and time elapsed caculation¶
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t7=time()
print "SVM"
svc = SVC()
clf_svc=svc.fit(X_train, y_train)
print "Acurracy: ", clf_svc.score(X_test,y_test)
t8=time()
print "time elapsed: ", t8-t7
cross validation for SVM¶
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tt7=time()
print "cross result========"
scores = cross_validation.cross_val_score(svc,X,y, cv=5)
print scores
print scores.mean()
tt8=time()
print "time elapsed: ", tt7-tt6
print "\n"
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from sklearn.svm import SVC
from sklearn.cross_validation import cross_val_score
from sklearn.pipeline import Pipeline
from sklearn import grid_search
svc = SVC()
parameters = {'kernel':('linear', 'rbf'), 'C':[1, 10]}
grid = grid_search.GridSearchCV(svc, parameters, n_jobs=-1, verbose=1, scoring='accuracy')
grid.fit(X_train, y_train)
print 'Best score: %0.3f' % grid.best_score_
print 'Best parameters set:'
best_parameters = grid.best_estimator_.get_params()
for param_name in sorted(parameters.keys()):
print '\t%s: %r' % (param_name, best_parameters[param_name])
predictions = grid.predict(X_test)
print classification_report(y_test, predictions)
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pipeline = Pipeline([
('clf', SVC(kernel='linear', gamma=0.01, C=10))
])
parameters = {
'clf__gamma': (0.01, 0.03, 0.1, 0.3, 1),
'clf__C': (0.1, 0.3, 1, 3, 10, 30),
}
grid_search = GridSearchCV(pipeline, parameters, n_jobs=-1, verbose=1, scoring='accuracy')
grid_search.fit(X_train, y_train)
print 'Best score: %0.3f' % grid_search.best_score_
print 'Best parameters set:'
best_parameters = grid_search.best_estimator_.get_params()
for param_name in sorted(parameters.keys()):
print '\t%s: %r' % (param_name, best_parameters[param_name])
predictions = grid_search.predict(X_test)
print classification_report(y_test, predictions)