This document summarizes a Chainer meetup where Yuta Kashino presented on PyTorch. Key points discussed include: - Yuta Kashino is the CEO of BakFoo, Inc. and discussed his background in astrophysics, Zope, and Python. - PyTorch was introduced as an alternative to Chainer and TensorFlow that is Pythonic and defines models dynamically through code. - PyTorch uses autograd to track gradients like Chainer but with Pythonic APIs and integration with NumPy for efficient operations. - Similarities between PyTorch and Chainer were highlighted around defining models as chains of functions, GPU support, and optimizer libraries. - Resources for learning more about PyTorch were provided, including tutorials on their website and courses on

1. 2017-09-30@ Chainer Meet UP

2. Yuta Kashino ( )
BakFoo, Inc. CEO
Astro Physics /Observational Cosmology
Zope / Python
Realtime Data Platform for Enterprise / Prototyping

3. arXiv
PyCon2015
Python
PyCon2016
PyCon2017 DNN PPL Edward
@yutakashino
Yuta Kashino ( )

4. Dr. Strangelove
- Dr. Strangelove or: How I Learned to Stop Worring
and Love the Bomb
-
- 1964
-
-
- …

6. …
TensorFlow Fold
Dynamic: Define By Run
Static: Define AND Run

7. TensorFlow Fold
Dynamic: Define By Run

8. …

10. PyTorch
- Torch 7 Chainer
-
- Adam Paszke
- Sam Gross
- Soumith Chintala
- NYU FBAIR
- 2017 2 v0.1.6

11. PyTorch
- 2017 2 v0.1.6
Google Trend

12. PyTorch
- TF/Keras …
Google Trend

13. PyTorch
- 2017 2 v0.1.6
Google Trend

16. - GPU(CUDA)
- Define by Run:
- Pythonic + python
http://pytorch.org/tutorials/advanced/numpy_extensions_tutorial.html

17. autograd.Variable
-
- data, grad (, grad_fn)
- chainer Variable
- autograd.Variables Chainer fork
- backward()
data grad
grad_fn

18. autograd.Variable
data grad
grad_fn
x
data grad
grad_fn
y
data grad
grad_fn
z

19. autograd …
- NLP DyNet 10
- Python addmm
- ATen
-
https://twitter.com/kchonyc/status/899832376955744257
https://github.com/zdevito/aten
https://goo.gl/Tujudr

21. - torcn.nn
chainer.Chain
chainer.links
chainer.functions

22. chainer.ChainList

23. GPU
- CPU → GPU: Variable cuda()
- GPU → CPU: cpu()
chainer

24. Chainer
- Chainer
- GPU Chainer
- Chainer
- torch.optim = chainer.optimizers
- …
- pytorch/tnt = chainer.training
- Pythonic …
https://github.com/pytorch/tnt

25. Chainer

27. - PyTorch
- PyTorch
- The Incredible PyTorch
https://github.com/ritchieng/the-incredible-pytorch

28. - arXiv
→
→
- →

29. -
- StackOverFlow
http://pytorch.org/tutorials/
https://discuss.pytorch.org/latest

30. - Practical Deep Learning with PyTorch on Udemy
-
- fast.ai
https://www.udemy.com/practical-deep-learning-with-pytorch
http://www.fast.ai/2017/09/08/introducing-pytorch-for-fastai/

33. Questions
kashino@bakfoo.com
@yutakashino

34. BakFoo, Inc.
NHK NMAPS: +

35. BakFoo, Inc.
PyConJP 2015
Python

36. BakFoo, Inc.

37. BakFoo, Inc.
: SNS +