p186_grid_search.py

'''
Created on Jul 8, 2016 grid_search.py
    Grid search does a brute force train and test of sample data, trying
    a grid of parameters.
    
    The SVM attempts to maximize the margin of error between linearly 
    separable feature sets.

from Python Machine Learning by Sebastian Raschka under the following license

The MIT License (MIT)

Copyright (c) 2015, 2016 SEBASTIAN RASCHKA (mail@sebastianraschka.com)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

@author: richard lyman
'''
import ocr_utils
from sklearn.preprocessing import StandardScaler
from sklearn.pipeline import Pipeline
from sklearn.grid_search import GridSearchCV
from sklearn.svm import SVC

if __name__ == '__main__':	

    y_train, X_train, y_test,  X_test, labels  = ocr_utils.load_E13B(chars_to_train = (48,51) , test_size=0.3, columns=(9,17), random_state=0) 

    pipe_svc = Pipeline([('scl', StandardScaler()),
                ('clf', SVC(random_state=1))])

    param_range = [0.0001, 0.001, 0.01, 0.1, 1.0, 10.0, 100.0, 1000.0]

    param_grid = [{'clf__C': param_range, 
                   'clf__kernel': ['linear']},
                     {'clf__C': param_range, 
                      'clf__gamma': param_range, 
                      'clf__kernel': ['rbf']}]

    gs = GridSearchCV(estimator=pipe_svc, 
                      param_grid=param_grid, 
                      scoring='accuracy', 
                      cv=10,
                      n_jobs=-1)
    gs = gs.fit(X_train, y_train)

    print('Support Vector Machine Grid Search best score: {}'.format(gs.best_score_))
    print('Support Vector Machine Grid Search best params: {}'.format(sorted(gs.best_params_.items())))

    clf = gs.best_estimator_
    clf.fit(X_train, y_train)
    print('Support Vector Machine Test accuracy: %.3f' % clf.score(X_test, y_test))

    print ('\n########################### No Errors ####################################')