def linreg_ccv_plot_roc(num_folds):
global data
folds = pd.create_folds(data, num_folds)
classifier = LinearRegression()
mean_tpr = 0.0
mean_fpr = np.linspace(0, 1, 100)
all_tpr = []
for i in range(num_folds):
test_x, test_y, train_x, train_y = pd.split_into_sets(data, folds, i)
probs = classifier.fit(train_x, train_y).predict(test_x)
fpr, tpr, thresholds = roc_curve(test_y, probs) #takes, y_true and y_score
mean_tpr += interp(mean_fpr, fpr, tpr)
mean_tpr[0] = 0.0
roc_auc = auc(fpr, tpr)
plt.plot(fpr, tpr, lw=1, label='ROC fold %d (area = %0.2f)' % (i, roc_auc))
plt.plot([0, 1], [0, 1], '--', color=(0.6, 0.6, 0.6), label='Luck')
mean_tpr /= len(folds)
mean_tpr[-1] = 1.0
mean_auc = auc(mean_fpr, mean_tpr)
plt.plot(mean_fpr, mean_tpr, 'k--',
label='Mean ROC (area = %0.2f)' % mean_auc, lw=2)
plt.xlim([-0.05, 1.05])
plt.ylim([-0.05, 1.05])
plt.xlabel('False Positive Rate')
plt.ylabel('True Positive Rate')
plt.title('%d-fold Clustered Cross-Validation' % num_folds)
plt.legend(loc="lower right")
plt.show()
def precision_recall_curve(num_folds): #w ccv 10fold
#haven't tested that this works yet
global data
folds = pd.create_folds(data, num_folds)
classifier = LogisticRegression()
for j in range(num_folds):
test_x, test_y, train_x, train_y = pd.split_into_sets(data, folds, j)
probs = classifier.fit(train_x, train_y).predict_proba(test_x)
precision, recall, _ = precision_recall_curve(test_y, probs[:, 1])
print precision
print recall
precision = dict()
recall = dict()
average_precision = dict()
#for i in range(n_classes):
for i in range (2): #2 classes?
precision[i], recall[i], _ = precision_recall_curve(test_y, probs[:, 1])
average_precision[i] = average_precision_score(test_y, probs[:, 1])
# Compute micro-average ROC curve and ROC area
precision["micro"], recall["micro"], _ = precision_recall_curve(test_y.ravel(), probs[:, 1].ravel())
average_precision["micro"] = average_precision_score(test_y, probs[:, 1],
average="micro")
# Plot Precision-Recall curve
plt.clf()
plt.plot(recall[0], precision[0], label='Precision-Recall curve')
plt.xlabel('Recall')
plt.ylabel('Precision')
plt.ylim([0.0, 1.05])
plt.xlim([0.0, 1.0])
plt.title('Precision-Recall example: AUC={0:0.2f}'.format(average_precision[0]))
plt.legend(loc="lower left")
plt.show()
# Plot Precision-Recall curve for each class
plt.clf()
plt.plot(recall["micro"], precision["micro"],
label='micro-average Precision-recall curve (area = {0:0.2f})'
''.format(average_precision["micro"]))
# for i in range(n_classes):
for i in range(2): #same deal
plt.plot(recall[i], precision[i],
label='Precision-recall curve of class {0} (area = {1:0.2f})'
''.format(i, average_precision[i]))
plt.xlim([0.0, 1.0])
plt.ylim([0.0, 1.05])
plt.xlabel('Recall')
plt.ylabel('Precision')
plt.title('Extension of Precision-Recall curve to multi-class')
plt.legend(loc="lower right")
plt.show()
def logreg_precision_recall_ccv(num_folds):
global data
folds = pd.create_folds(data, num_folds)
classifier = LogisticRegression()
mean_recall = 0.0
mean_precision = 0.0
for i in range(num_folds):
test_x, test_y, train_x, train_y = pd.split_into_sets(data, folds, i)
probs = classifier.fit(train_x, train_y).predict_proba(test_x)
y_pred = [1 if x >= .5 else 0 for x in probs[:, 1]]
# print test_y
# print y_pred
recall = recall_score(test_y, y_pred) #y_true, y_pred
# print 'RECALL'
# print recall
precision = precision_score(test_y, y_pred)
# print 'PRECISION'
# print precision
#
mean_recall += recall
mean_precision += precision
mean_precision /= len(folds)
mean_recall /= len(folds)
print "MEAN PRECISION"
print mean_precision
print "MEAN RECALL"
print mean_recall
