def compute_accuracy(self, X, y):
"""
Computes accuracy on provided data using mini-batches
"""
indices = np.arange(X.shape[0])
sections = np.arange(self.batch_size, X.shape[0], self.batch_size)
batches_indices = np.array_split(indices, sections)
pred = np.zeros_like(y)
for batch_indices in batches_indices:
batch_X = X[batch_indices]
pred_batch = self.model.predict(batch_X)
pred[batch_indices] = pred_batch
return multiclass_accuracy(pred, y)
def fit(self,
X,
y,
batch_size=100,
learning_rate=1e-7,
reg=1e-5,
epochs=1):
"""
Trains linear classifier
Arguments:
X, np array (num_samples, num_features) - training data
y, np array of int (num_samples) - labels
batch_size, int - batch size to use
learning_rate, float - learning rate for gradient descent
reg, float - L2 regularization strength
epochs, int - number of epochs
"""
num_train = X.shape[0]
num_features = X.shape[1]
num_classes = np.max(y) + 1
if self.W is None:
self.W = 0.001 * np.random.randn(num_features, num_classes)
loss_history = []
loss = 0
for epoch in range(epochs):
shuffled_indices = np.arange(num_train)
np.random.shuffle(shuffled_indices)
sections = np.arange(batch_size, num_train, batch_size)
batches_indices = np.array_split(shuffled_indices, sections)
for i in range(len(batches_indices)):
loss, dW_dL = linear_softmax(X, self.W, y)
reg_loss, dW_dR = l2_regularization(self.W, reg)
self.W -= learning_rate * (dW_dL + dW_dR)
print("Epoch %i, loss: %f, acur: %f" %
(epoch, loss, multiclass_accuracy(self.predict(X), y)))
loss_history.append(loss)
return loss_history
def compute_accuracy(self, X, y):
'''
Computes accuracy on provided data using mini-batches
'''
indices = np.arange(X.shape[0])
sections = np.arange(self.batch_size, X.shape[0], self.batch_size)
batches_indices = np.array_split(indices, sections)
pred = np.zeros_like(y)
for batch_indices in batches_indices:
batch_X = X[batch_indices]
pred_batch = self.model.predict(batch_X)
pred[batch_indices] = pred_batch
# print(f"\n prediction {np.unique(pred, return_counts=True)}")
# print(f"ground through {np.unique(y, return_counts=True)} \n")
# param_ = self.model.Conv1.W
# before_opt = param_.value[:2, :2]
# print(f"PREDICT stage Conv1_W value: \n {before_opt} \n")
# print(f"PREDICT stage Conv1_dW: \n {param_.grad[:2, :2]} \n")
return multiclass_accuracy(pred, y)
loss_with_reg, loss
), "Loss with regularization (%2.4f) should be higher than without it (%2.4f)!" % (
loss, loss_with_reg)
check_model_gradient(model_with_reg, train_X[:2], train_y[:2])
#%% [markdown]
# Также реализуем функцию предсказания (вычисления значения) модели на новых данных.
#
# Какое значение точности мы ожидаем увидеть до начала тренировки?
#%%
# Finally, implement predict function!
# What would be the value we expect?
multiclass_accuracy(model_with_reg.predict(train_X[:30]), train_y[:30])
#%% [markdown]
# # Допишем код для процесса тренировки
#%%
from trainer import Trainer, Dataset
from optim import SGD
from modelGridSearch import search_model
model = TwoLayerNet(n_input=train_X.shape[1],
n_output=10,
hidden_layer_size=100,
reg=1e-1)
dataset = Dataset(train_X, train_y, val_X, val_y)
trainer = Trainer(model, dataset, SGD())
loss_history = classifier.fit(train_X,
train_y,
epochs=10,
learning_rate=default_learning_rate,
batch_size=batch_size,
reg=default_reg_strength)
#%%
# let's look at the loss history!
plt.plot(loss_history)
#%%
# Let's check how it performs on validation set
pred = classifier.predict(val_X)
accuracy = multiclass_accuracy(pred, val_y)
print("Accuracy: ", accuracy)
# Now, let's train more and see if it performs better
loss_history = classifier.fit(train_X,
train_y,
epochs=num_epochs,
learning_rate=default_learning_rate,
batch_size=batch_size,
reg=default_reg_strength)
pred = classifier.predict(val_X)
accuracy = multiclass_accuracy(pred, val_y)
print("Accuracy after training for {} epochs: {}".format(num_epochs, accuracy))
#%% [markdown]
# ### Как и раньше, используем кросс-валидацию для подбора гиперпараметтов.
prediction = best_knn_classifier.predict(binary_test_X, num_loops=1)
precision, recall, f1, accuracy = binary_classification_metrics(
prediction, binary_test_y)
print("Best KNN with k = %s" % best_k)
print("Accuracy: %4.2f, Precision: %4.2f, Recall: %4.2f, F1: %4.2f" %
(accuracy, precision, recall, f1))
train_X = train_X.reshape(train_X.shape[0], -1)
test_X = test_X.reshape(test_X.shape[0], -1)
knn_classifier = KNN(k=1)
knn_classifier.fit(train_X, train_y)
predict = knn_classifier.predict(test_X, num_loops=1)
accuracy = multiclass_accuracy(predict, test_y)
print("Accuracy: %4.2f" % accuracy)
num_folds = 5
fold_step = int(train_X.shape[0] // num_folds)
ranges = list(range(0, train_X.shape[0], fold_step))
train_folds_X = [
train_X[ranges[i]:ranges[i + 1]] for i in range(0,
len(ranges) - 1)
]
train_folds_y = [
train_y[ranges[i]:ranges[i + 1]] for i in range(0,
len(ranges) - 1)
]
test_X = test_X.reshape(test_X.shape[0], -1)
knn_classifier = KNN(k=1)
knn_classifier.fit(train_X, train_y)
#%%
dists = knn_classifier.compute_distances_no_loops(test_X)
num_test = dists.shape[0]
k_closest_indices = np.argpartition(dists, knn_classifier.k, axis=1)[:,:knn_classifier.k]
k_closest_indices.shape
#%%
predict = knn_classifier.predict(test_X)
#%%
accuracy = multiclass_accuracy(predict, test_y)
print("Accuracy: %4.2f" % accuracy)
#%% [markdown]
# Снова кросс-валидация. Теперь нашей основной метрикой стала точность (accuracy), и ее мы тоже будем усреднять по всем фолдам.
#%%
# Find the best k using cross-validation based on accuracy
num_folds = 5
train_folds_X = []
train_folds_y = []
#%%
data_to_fold = train_X
answers_to_fold = train_y
fold_size = train_y.shape[0]//num_folds
# Now let's use all 10 classes
train_X = train_X.reshape(train_X.shape[0], -1)
test_X = test_X.reshape(test_X.shape[0], -1)
knn_classifier = KNN(k=1)
knn_classifier.fit(train_X, train_y)
# In[43]:
# TODO: Implement predict_labels_multiclass
predict = knn_classifier.predict(test_X)
# In[44]:
# TODO: Implement multiclass_accuracy
accuracy = multiclass_accuracy(predict, test_y)
print("Accuracy: %4.2f" % accuracy)
# Снова кросс-валидация. Теперь нашей основной метрикой стала точность (accuracy), и ее мы тоже будем усреднять по всем фолдам.
# In[47]:
# Find the best k using cross-validation based on accuracy
num_folds = 5
train_folds_X = []
train_folds_y = []
# TODO: split the training data in 5 folds and store them in train_folds_X/train_folds_y
train_folds_X = np.array_split(binary_train_X, num_folds)
train_folds_y = np.array_split(binary_train_y, num_folds)
