I am getting extremely poor SVM performance on a simple binary learning
problem. I am doing an exhaustive grid search, but most of the AUC scores I
obtain are below 0.5 (basically the performance of a random classifier)

Here is my feature matrix X:
https://gist.github.com/ribonoous/5952080

and here is my label vector y:
https://gist.github.com/ribonoous/5952067

and here is my code (also available in this
gist<https://gist.github.com/ribonoous/5952103>
):

# Set the parameters by cross-validation
my_exps = np.arange(-20,20, 2)
my_values = np.exp(C_exps)

tuned_parameters = [{'kernel': ['rbf'], 'gamma': my_values,
                     'C': my_values},
                    {'kernel': ['linear'], 'C': my_values}]

scores = [

    ('auc_score', auc_score),
]

from sklearn.cross_validation import StratifiedKFold
skf = StratifiedKFold(y,5)

for score_name, score_func in scores:
    clf = GridSearchCV(SVC(C=1), tuned_parameters,
score_func=score_func,verbose=2, n_jobs=1, cv=skf)


    clf.fit(X, y)


    print "Grid scores:"

    pprint(clf.grid_scores_)


    print "Best score:"

    pprint(clf.best_score_)

    print "Classification report for the best estimator: "

    print clf.best_estimator_


Am I using scikit-learn incorrectly? Is this expected?

Thank you,

Josh
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