Files
project5-machinelearning/backend.py
T
2019-05-01 00:07:11 -07:00

448 lines
18 KiB
Python

import collections
import os
import time
import os
import matplotlib.pyplot as plt
import numpy as np
import nn
use_graphics = True
def maybe_sleep_and_close(seconds):
if use_graphics and plt.get_fignums():
time.sleep(seconds)
for fignum in plt.get_fignums():
fig = plt.figure(fignum)
plt.close(fig)
try:
# This raises a TclError on some Windows machines
fig.canvas.start_event_loop(1e-3)
except:
pass
def get_data_path(filename):
path = os.path.join(
os.path.dirname(__file__), os.pardir, "data", filename)
if not os.path.exists(path):
path = os.path.join(
os.path.dirname(__file__), "data", filename)
if not os.path.exists(path):
path = os.path.join(
os.path.dirname(__file__), filename)
if not os.path.exists(path):
raise Exception("Could not find data file: {}".format(filename))
return path
class Dataset(object):
def __init__(self, x, y):
assert isinstance(x, np.ndarray)
assert isinstance(y, np.ndarray)
assert np.issubdtype(x.dtype, np.floating)
assert np.issubdtype(y.dtype, np.floating)
assert x.ndim == 2
assert y.ndim == 2
assert x.shape[0] == y.shape[0]
self.x = x
self.y = y
def iterate_once(self, batch_size):
assert isinstance(batch_size, int) and batch_size > 0, (
"Batch size should be a positive integer, got {!r}".format(
batch_size))
assert self.x.shape[0] % batch_size == 0, (
"Dataset size {:d} is not divisible by batch size {:d}".format(
self.x.shape[0], batch_size))
index = 0
while index < self.x.shape[0]:
x = self.x[index:index + batch_size]
y = self.y[index:index + batch_size]
yield nn.Constant(x), nn.Constant(y)
index += batch_size
def iterate_forever(self, batch_size):
while True:
yield from self.iterate_once(batch_size)
def get_validation_accuracy(self):
raise NotImplementedError(
"No validation data is available for this dataset. "
"In this assignment, only the Digit Classification and Language "
"Identification datasets have validation data.")
class PerceptronDataset(Dataset):
def __init__(self, model):
points = 500
x = np.hstack([np.random.randn(points, 2), np.ones((points, 1))])
y = np.where(x[:, 0] + 2 * x[:, 1] - 1 >= 0, 1.0, -1.0)
super().__init__(x, np.expand_dims(y, axis=1))
self.model = model
self.epoch = 0
if use_graphics:
fig, ax = plt.subplots(1, 1)
limits = np.array([-3.0, 3.0])
ax.set_xlim(limits)
ax.set_ylim(limits)
positive = ax.scatter(*x[y == 1, :-1].T, color="red", marker="+")
negative = ax.scatter(*x[y == -1, :-1].T, color="blue", marker="_")
line, = ax.plot([], [], color="black")
text = ax.text(0.03, 0.97, "", transform=ax.transAxes, va="top")
ax.legend([positive, negative], [1, -1])
plt.show(block=False)
self.fig = fig
self.limits = limits
self.line = line
self.text = text
self.last_update = time.time()
def iterate_once(self, batch_size):
self.epoch += 1
for i, (x, y) in enumerate(super().iterate_once(batch_size)):
yield x, y
if use_graphics and time.time() - self.last_update > 0.01:
w = self.model.get_weights().data.flatten()
limits = self.limits
if w[1] != 0:
self.line.set_data(limits, (-w[0] * limits - w[2]) / w[1])
elif w[0] != 0:
self.line.set_data(np.full(2, -w[2] / w[0]), limits)
else:
self.line.set_data([], [])
self.text.set_text(
"epoch: {:,}\npoint: {:,}/{:,}\nweights: {}".format(
self.epoch, i * batch_size + 1, len(self.x), w))
self.fig.canvas.draw_idle()
self.fig.canvas.start_event_loop(1e-3)
self.last_update = time.time()
class RegressionDataset(Dataset):
def __init__(self, model):
x = np.expand_dims(np.linspace(-2 * np.pi, 2 * np.pi, num=200), axis=1)
np.random.RandomState(0).shuffle(x)
self.argsort_x = np.argsort(x.flatten())
y = np.sin(x)
super().__init__(x, y)
self.model = model
self.processed = 0
if use_graphics:
fig, ax = plt.subplots(1, 1)
ax.set_xlim(-2 * np.pi, 2 * np.pi)
ax.set_ylim(-1.4, 1.4)
real, = ax.plot(x[self.argsort_x], y[self.argsort_x], color="blue")
learned, = ax.plot([], [], color="red")
text = ax.text(0.03, 0.97, "", transform=ax.transAxes, va="top")
ax.legend([real, learned], ["real", "learned"])
plt.show(block=False)
self.fig = fig
self.learned = learned
self.text = text
self.last_update = time.time()
def iterate_once(self, batch_size):
for x, y in super().iterate_once(batch_size):
yield x, y
self.processed += batch_size
if use_graphics and time.time() - self.last_update > 0.1:
predicted = self.model.run(nn.Constant(self.x)).data
loss = self.model.get_loss(
nn.Constant(self.x), nn.Constant(self.y)).data
self.learned.set_data(self.x[self.argsort_x], predicted[self.argsort_x])
self.text.set_text("processed: {:,}\nloss: {:.6f}".format(
self.processed, loss))
self.fig.canvas.draw_idle()
self.fig.canvas.start_event_loop(1e-3)
self.last_update = time.time()
class DigitClassificationDataset(Dataset):
def __init__(self, model):
mnist_path = get_data_path("mnist.npz")
with np.load(mnist_path) as data:
train_images = data["train_images"]
train_labels = data["train_labels"]
test_images = data["test_images"]
test_labels = data["test_labels"]
assert len(train_images) == len(train_labels) == 60000
assert len(test_images) == len(test_labels) == 10000
self.dev_images = test_images[0::2]
self.dev_labels = test_labels[0::2]
self.test_images = test_images[1::2]
self.test_labels = test_labels[1::2]
train_labels_one_hot = np.zeros((len(train_images), 10))
train_labels_one_hot[range(len(train_images)), train_labels] = 1
super().__init__(train_images, train_labels_one_hot)
self.model = model
self.epoch = 0
if use_graphics:
width = 20 # Width of each row expressed as a multiple of image width
samples = 100 # Number of images to display per label
fig = plt.figure()
ax = {}
images = collections.defaultdict(list)
texts = collections.defaultdict(list)
for i in reversed(range(10)):
ax[i] = plt.subplot2grid((30, 1), (3 * i, 0), 2, 1,
sharex=ax.get(9))
plt.setp(ax[i].get_xticklabels(), visible=i == 9)
ax[i].set_yticks([])
ax[i].text(-0.03, 0.5, i, transform=ax[i].transAxes,
va="center")
ax[i].set_xlim(0, 28 * width)
ax[i].set_ylim(0, 28)
for j in range(samples):
images[i].append(ax[i].imshow(
np.zeros((28, 28)), vmin=0, vmax=1, cmap="Greens",
alpha=0.3))
texts[i].append(ax[i].text(
0, 0, "", ha="center", va="top", fontsize="smaller"))
ax[9].set_xticks(np.linspace(0, 28 * width, 11))
ax[9].set_xticklabels(
["{:.1f}".format(num) for num in np.linspace(0, 1, 11)])
ax[9].tick_params(axis="x", pad=16)
ax[9].set_xlabel("Probability of Correct Label")
status = ax[0].text(
0.5, 1.5, "", transform=ax[0].transAxes, ha="center",
va="bottom")
plt.show(block=False)
self.width = width
self.samples = samples
self.fig = fig
self.images = images
self.texts = texts
self.status = status
self.last_update = time.time()
def iterate_once(self, batch_size):
self.epoch += 1
for i, (x, y) in enumerate(super().iterate_once(batch_size)):
yield x, y
if use_graphics and time.time() - self.last_update > 1:
dev_logits = self.model.run(nn.Constant(self.dev_images)).data
dev_predicted = np.argmax(dev_logits, axis=1)
dev_probs = np.exp(nn.SoftmaxLoss.log_softmax(dev_logits))
dev_accuracy = np.mean(dev_predicted == self.dev_labels)
self.status.set_text(
"epoch: {:d}, batch: {:d}/{:d}, validation accuracy: "
"{:.2%}".format(
self.epoch, i, len(self.x) // batch_size, dev_accuracy))
for i in range(10):
predicted = dev_predicted[self.dev_labels == i]
probs = dev_probs[self.dev_labels == i][:, i]
linspace = np.linspace(
0, len(probs) - 1, self.samples).astype(int)
indices = probs.argsort()[linspace]
for j, (prob, image) in enumerate(zip(
probs[indices],
self.dev_images[self.dev_labels == i][indices])):
self.images[i][j].set_data(image.reshape((28, 28)))
left = prob * (self.width - 1) * 28
if predicted[indices[j]] == i:
self.images[i][j].set_cmap("Greens")
self.texts[i][j].set_text("")
else:
self.images[i][j].set_cmap("Reds")
self.texts[i][j].set_text(predicted[indices[j]])
self.texts[i][j].set_x(left + 14)
self.images[i][j].set_extent([left, left + 28, 0, 28])
self.fig.canvas.draw_idle()
self.fig.canvas.start_event_loop(1e-3)
self.last_update = time.time()
def get_validation_accuracy(self):
dev_logits = self.model.run(nn.Constant(self.dev_images)).data
dev_predicted = np.argmax(dev_logits, axis=1)
dev_accuracy = np.mean(dev_predicted == self.dev_labels)
return dev_accuracy
class LanguageIDDataset(Dataset):
def __init__(self, model):
self.model = model
data_path = get_data_path("lang_id.npz")
with np.load(data_path) as data:
self.chars = data['chars']
self.language_codes = data['language_codes']
self.language_names = data['language_names']
self.train_x = data['train_x']
self.train_y = data['train_y']
self.train_buckets = data['train_buckets']
self.dev_x = data['dev_x']
self.dev_y = data['dev_y']
self.dev_buckets = data['dev_buckets']
self.test_x = data['test_x']
self.test_y = data['test_y']
self.test_buckets = data['test_buckets']
self.epoch = 0
self.bucket_weights = self.train_buckets[:,1] - self.train_buckets[:,0]
self.bucket_weights = self.bucket_weights / float(self.bucket_weights.sum())
self.chars_print = self.chars
try:
print(u"Alphabet: {}".format(u"".join(self.chars)))
except UnicodeEncodeError:
self.chars_print = "abcdefghijklmnopqrstuvwxyzaaeeeeiinoouuacelnszz"
print("Alphabet: " + self.chars_print)
self.chars_print = list(self.chars_print)
print("""
NOTE: Your terminal does not appear to support printing Unicode characters.
For the purposes of printing to the terminal, some of the letters in the
alphabet above have been substituted with ASCII symbols.""".strip())
print("")
# Select some examples to spotlight in the monitoring phase (3 per language)
spotlight_idxs = []
for i in range(len(self.language_names)):
idxs_lang_i = np.nonzero(self.dev_y == i)[0]
idxs_lang_i = np.random.choice(idxs_lang_i, size=3, replace=False)
spotlight_idxs.extend(list(idxs_lang_i))
self.spotlight_idxs = np.array(spotlight_idxs, dtype=int)
# Templates for printing updates as training progresses
max_word_len = self.dev_x.shape[1]
max_lang_len = max([len(x) for x in self.language_names])
self.predicted_template = u"Pred: {:<NUM}".replace('NUM',
str(max_lang_len))
self.word_template = u" "
self.word_template += u"{:<NUM} ".replace('NUM', str(max_word_len))
self.word_template += u"{:<NUM} ({:6.1%})".replace('NUM', str(max_lang_len))
self.word_template += u" {:<NUM} ".replace('NUM',
str(max_lang_len + len('Pred: ')))
for i in range(len(self.language_names)):
self.word_template += u"|{}".format(self.language_codes[i])
self.word_template += "{probs[" + str(i) + "]:4.0%}"
self.last_update = time.time()
def _encode(self, inp_x, inp_y):
xs = []
for i in range(inp_x.shape[1]):
if np.all(inp_x[:,i] == -1):
break
assert not np.any(inp_x[:,i] == -1), (
"Please report this error in the project: batching by length was done incorrectly in the provided code")
x = np.eye(len(self.chars))[inp_x[:,i]]
xs.append(nn.Constant(x))
y = np.eye(len(self.language_names))[inp_y]
y = nn.Constant(y)
return xs, y
def _softmax(self, x):
exp = np.exp(x - np.max(x, axis=-1, keepdims=True))
return exp / np.sum(exp, axis=-1, keepdims=True)
def _predict(self, split='dev'):
if split == 'dev':
data_x = self.dev_x
data_y = self.dev_y
buckets = self.dev_buckets
else:
data_x = self.test_x
data_y = self.test_y
buckets = self.test_buckets
all_predicted = []
all_correct = []
for bucket_id in range(buckets.shape[0]):
start, end = buckets[bucket_id]
xs, y = self._encode(data_x[start:end], data_y[start:end])
predicted = self.model.run(xs)
all_predicted.extend(list(predicted.data))
all_correct.extend(list(data_y[start:end]))
all_predicted_probs = self._softmax(np.asarray(all_predicted))
all_predicted = np.asarray(all_predicted).argmax(axis=-1)
all_correct = np.asarray(all_correct)
return all_predicted_probs, all_predicted, all_correct
def iterate_once(self, batch_size):
assert isinstance(batch_size, int) and batch_size > 0, (
"Batch size should be a positive integer, got {!r}".format(
batch_size))
assert self.train_x.shape[0] >= batch_size, (
"Dataset size {:d} is smaller than the batch size {:d}".format(
self.train_x.shape[0], batch_size))
self.epoch += 1
for iteration in range(self.train_x.shape[0] // batch_size):
bucket_id = np.random.choice(self.bucket_weights.shape[0], p=self.bucket_weights)
example_ids = self.train_buckets[bucket_id, 0] + np.random.choice(
self.train_buckets[bucket_id, 1] - self.train_buckets[bucket_id, 0],
size=batch_size)
yield self._encode(self.train_x[example_ids], self.train_y[example_ids])
if use_graphics and time.time() - self.last_update > 0.5:
dev_predicted_probs, dev_predicted, dev_correct = self._predict()
dev_accuracy = np.mean(dev_predicted == dev_correct)
print("epoch {:,} iteration {:,} validation-accuracy {:.1%}".format(
self.epoch, iteration, dev_accuracy))
for idx in self.spotlight_idxs:
correct = (dev_predicted[idx] == dev_correct[idx])
word = u"".join([self.chars_print[ch] for ch in self.dev_x[idx] if ch != -1])
print(self.word_template.format(
word,
self.language_names[dev_correct[idx]],
dev_predicted_probs[idx, dev_correct[idx]],
"" if correct else self.predicted_template.format(
self.language_names[dev_predicted[idx]]),
probs=dev_predicted_probs[idx,:],
))
self.last_update = time.time()
def get_validation_accuracy(self):
dev_predicted_probs, dev_predicted, dev_correct = self._predict()
dev_accuracy = np.mean(dev_predicted == dev_correct)
return dev_accuracy
def main():
import models
model = models.PerceptronModel(3)
dataset = PerceptronDataset(model)
model.train(dataset)
model = models.RegressionModel()
dataset = RegressionDataset(model)
model.train(dataset)
model = models.DigitClassificationModel()
dataset = DigitClassificationDataset(model)
model.train(dataset)
model = models.LanguageIDModel()
dataset = LanguageIDDataset(model)
model.train(dataset)
if __name__ == "__main__":
main()