def qda_classifier(train_XY, priors=None):
train_X, train_Y = save_XY(train_XY)
qda = QuadraticDiscriminantAnalysis(priors=priors).fit(train_X, train_Y)
def classify(test_X):
test_X = to_ndarray(test_X)
return qda.predict(test_X)
return classify
def random_forest_classifier(train_XY, priors=None):
train_X, train_Y = save_XY(train_XY)
forest = RandomForestClassifier(n_jobs=-1).fit(train_X, train_Y)
def classify(test_X):
test_X = to_ndarray(test_X)
return forest.predict(test_X)
return classify
def run_classification(config):
embeddingconfig, gramconfig, runconfig = config
label_num = len(gramconfig.skipwords) + 1
XY = iter_XY(config)
occurence_nums = [0 for label in range(0, label_num)]
def occurence(y):
occurence_nums[y] += 1
XY = on_the_side(lambda xy: occurence(xy[1]), XY)
def priors():
total = sum(occurence_nums)
return [occurence_num / total for occurence_num in occurence_nums]
# per_label_test_size = 5000
test_XY = islice(XY, 5000)
# test_XY = n_from_each_group(XY, per_label_test_size, key=lambda xy: xy[1], \
# group_labels=[lbl for lbl in range(label_num)])
test_X, test_Y = save_XY(test_XY)
train_XY = None
train_priors = None
priors_ = priors()
if runconfig.train_with_priors:
train_priors = priors_
train_size_per_label = runconfig.train_size // label_num
train_XY = n_from_each_group(XY, train_size_per_label, key=lambda xy: xy[1])
else:
train_XY = islice(XY, runconfig.train_size)
classifier = classifiers[runconfig.classifier]
start_time = time()
classify = classifier(train_XY, priors=train_priors)
traintime = time() - start_time
start_time = time()
response_Y = classify(test_X)
testtime = time() - start_time
from_label = partial(label_to_word, gramconfig.skipwords)
test_Y = list(map(from_label, test_Y))
response_Y = list(map(from_label, response_Y))
histogram = classification_histogram(test_Y, response_Y)
result_priors = {from_label(lbl): priors_[lbl] for lbl in range(label_num)}
result = Result(traintime, testtime, result_priors, histogram)
return result
def logistic_regression_classifier(train_XY, multi_class, priors=None):
assert priors is None
train_X, train_Y = save_XY(train_XY)
solver = 'liblinear'
if multi_class == 'multinomial':
solver = 'newton-cg'
lgr = LogisticRegression(multi_class=multi_class, solver=solver, n_jobs=-1).fit(train_X, train_Y)
def classify(test_X):
test_X = to_ndarray(test_X)
return lgr.predict(test_X)
return classify
def nn_classifier(train_XY, k=1, priors=None):
# ignore priors
train_X, train_Y = save_XY(train_XY)
nn = NearestNeighbors(n_neighbors=k, metric='cosine', algorithm='brute', n_jobs=-1)
nn = nn.fit(train_X)
def classify(test_X):
test_X = to_ndarray(test_X)
response_Y = []
for neighbor_indices in nn.kneighbors(test_X, return_distance=False):
neighbor_labels = [train_Y[index] for index in neighbor_indices]
best_label = max(set(train_Y), key=lambda label: neighbor_labels.count(label))
response_Y.append(best_label)
return to_ndarray(response_Y, dtype=int)
return classify
