Introduction to PyTorch

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What is Pytorch?

Why might you want to try PyTorch?

Why might you want to try PyTorch?

NumPy

Why might you want to try PyTorch?

Celebrity endorsements

Dynamic computation graphs

Dynamic computation graphs

Sure but what does that really mean?

Dynamic computation graphs

Title Text

import numpy as np
import torch
from torch.autograd import Variable
model = torch.nn.Linear(1, 1)
loss_fn = torch.nn.MSELoss(size_average=False)
optimizer = torch.optim.SGD(model.parameters(), lr=0.01)
for t in range(10000):
    x = Variable(torch.from_numpy(np.random.random((1,1)).astype(np.float32)))
    y = x * 3
    y_pred = model(x)
    loss = loss_fn(y_pred, y)
    optimizer.zero_grad()
    loss.backward()
    optimizer.step()
    print loss.data[0]

Simple example PyTorch

Source: Tensorflow sucks

Title Text

import tensorflow as tf
import numpy as np
X = tf.placeholder("float")
Y = tf.placeholder("float")
W = tf.Variable(np.random.random(), name="weight")
pred = tf.multiply(X, W)
cost = tf.reduce_sum(tf.pow(pred-Y, 2))
optimizer = tf.train.GradientDescentOptimizer(0.01).minimize(cost)
init = tf.global_variables_initializer()
with tf.Session() as sess:
    sess.run(init)
    for t in range(10000):
        x = np.array(np.random.random()).reshape((1, 1, 1, 1))
        y = x * 3
        (_, c) = sess.run([optimizer, cost], feed_dict={X: x, Y: y})
        print c

Comparative code in Tensor Flow 

Source: Tensorflow sucks

In summary

Think about using PyTorch if you

https://slides.com/henrye/deck-2/