Section 2-1 - Support Vector Machines

We now replace the Random Forest model we used in Section 1 by Support Vector Machines.

Pandas - Extracting data

In [1]:
import pandas as pd
import numpy as np

df = pd.read_csv('../data/train.csv')

Pandas - Cleaning data

In [2]:
df = df.drop(['Name', 'Ticket', 'Cabin'], axis=1)

age_mean = df['Age'].mean()
df['Age'] = df['Age'].fillna(age_mean)

from scipy.stats import mode

mode_embarked = mode(df['Embarked'])[0][0]
df['Embarked'] = df['Embarked'].fillna(mode_embarked)

df['Gender'] = df['Sex'].map({'female': 0, 'male': 1}).astype(int)
df = pd.concat([df, pd.get_dummies(df['Embarked'], prefix='Embarked')], axis=1)

df = df.drop(['Sex', 'Embarked'], axis=1)

cols = df.columns.tolist()
cols = [cols[1]] + cols[0:1] + cols[2:]
df = df[cols]

train_data = df.values

Scikit-learn - Training the model

We simply set the model to be used as the Support Vector Classifier. We note that the clean syntax of Scikit-learn makes machine learning accessible.

In [3]:
from sklearn.svm import SVC

model = SVC(kernel='linear')
model =[0:,2:], train_data[0:,0])

Scikit-learn - Making predictions

In [4]:
df_test = pd.read_csv('../data/test.csv')

df_test = df_test.drop(['Name', 'Ticket', 'Cabin'], axis=1)

df_test['Age'] = df_test['Age'].fillna(age_mean)

fare_means = df.pivot_table('Fare', index='Pclass', aggfunc='mean')
df_test['Fare'] = df_test[['Fare', 'Pclass']].apply(lambda x:
                            fare_means[x['Pclass']] if pd.isnull(x['Fare'])
                            else x['Fare'], axis=1)

df_test['Gender'] = df_test['Sex'].map({'female': 0, 'male': 1}).astype(int)
df_test = pd.concat([df_test, pd.get_dummies(df_test['Embarked'], prefix='Embarked')],

df_test = df_test.drop(['Sex', 'Embarked'], axis=1)

test_data = df_test.values

output = model.predict(test_data[:,1:])

/Users/savarin/anaconda/envs/py27/lib/python2.7/site-packages/pandas/core/ FutureWarning: scalar indexers for index type Int64Index should be integers and not floating point

Pandas - Preparing for submission

In [5]:
result = np.c_[test_data[:,0].astype(int), output.astype(int)]

df_result = pd.DataFrame(result[:,0:2], columns=['PassengerId', 'Survived'])
df_result.to_csv('../results/titanic_2-1.csv', index=False)