HN user

skierscott

406 karma
Posts20
Comments160
View on HN
stsievert.com 6y ago

Visualization of Covid-19 infection rates

skierscott
1pts0
medium.com 8y ago

TensorFlow meets PyTorch with Eager execution

skierscott
3pts0
scottsievert.com 10y ago

Least squares and regularization

skierscott
13pts0
scottsievert.github.io 10y ago

Stepping from Matlab to Python

skierscott
2pts0
scottsievert.github.io 11y ago

Computer color is only kinda broken

skierscott
5pts0
scottsievert.github.io 11y ago

N dimensions, linear algebra, linear functions and closed-form solutions

skierscott
7pts0
scottsievert.github.io 11y ago

Applying eigenvalues to the Fibonacci problem

skierscott
3pts0
github.com 11y ago

Implementing XKCD #688

skierscott
2pts0
mathbabe.org 11y ago

I love math and I hate the Fields Medal

skierscott
3pts0
scottsievert.github.io 11y ago

Common Mathematical Misconceptions

skierscott
3pts0
scottsievert.github.io 11y ago

Simple Python Parallelism

skierscott
2pts0
most-advantageous.com 12y ago

Optimal Layout, another OSX window manager

skierscott
1pts0
www.nasa.gov 12y ago

Mysterious X-ray Signal Intrigues Astronomers

skierscott
2pts0
github.com 12y ago

Show HN: Swift Matrix Library

skierscott
3pts0
scottsievert.github.io 12y ago

Show HN: jem-press, easy-to-use static site generator

skierscott
2pts0
scottsievert.github.io 12y ago

FFTs and Optical Lenses

skierscott
55pts23
scottsievert.github.io 12y ago

Why are lasers speckled?

skierscott
1pts0
www.mplewis.com 12y ago

Real-world pathfinding visualization

skierscott
1pts0
scottsievert.github.io 12y ago

Scientific Python tips and tricks

skierscott
16pts5
nbviewer.ipython.org 13y ago

NumPy, Numba, Matlab and C

skierscott
2pts0

a low confidence score

Neural nets should return a low confidence score. But, the popular approach (described below) ignores that. Neural nets ignore confidence because of a technique called softmax [1].

This happens as the final operation of a neural net, and is required for training.

Softmax is a tool to make an array of positive numbers look like a probability distribution:

    out = x / x.sum()
x[i] is a class prediction, but x.sum() != 1. Say if the network was uncertain, x[cat, dog] = [0.03, 0.01]. These are small values that do not imply great confidence (the network was trained on vectors with out.sum() = 1. The network would predict “dog” using softmax because out[dog] = 0.75 > 0.25 = out[cat].

But then in inference/prediction, the confidence is ignored. What if x.sum() is small? That would imply that the network is uncertain.

[1] https://en.m.wikipedia.org/wiki/Softmax_function

> Going forward, GitHub will remain an open platform, which any developer can plug into and extend.

Does an “open platform” mean “open source” or “a plugin system”? I think making it open source would alleviate a lot of dev concerns.

“If you understand and agree, Apple and GCBD have the right to access your data stored on its servers. This includes permission sharing, exchange, and disclosure of all user data (including content) according to the application of the law.”

In other words, once the agreement is signed, GCBD — a company solely owned by the state — would get a key that can access all iCloud user data in China, legally.

What user data will this decrypt? Are iMessage and FaceTime still safe?

Project Euler 9 years ago

Not true. Infinite sums are not defined for series that don’t converge, and sum(1..n) does not converge as n => infinity.

Yes, you can play a nice trick with that sum if you ignore the fact that inf-inf is meaningless.

what has changed in Python 3.6 that they're happy to do this now when they were pissed off about it a couple years ago?

Most of mine have to do with developer productovity and I didn’t find until Python 3.5.

– @, the matmul operator

– fstrings (f”{foo}”)

– parameter typing (foo: int = 0) which has exciting work with Cython

– other async features. I forget what library it was (tensorflow?) but for Python 3 it had better async support

Was this was the anxiety that had been mentioned in the medical literature?

I don’t know. I’ve had a difference expierence with brain injury and anxiety. My recovery resulted in classic anxiety; I experienced social anxiety and depression.

Privacy 9 years ago

D’oh. I meant anonyomized (I would edit comment but can’t).

I’m doing research (not deployment) and have the same feeling. PyTorch has inspired a blog post [1], Tensorflow didn’t.

Briefly, the benefits of PyTorch are

* easy conversion to NumPy arrays (meaning rest of Python can be used!). This is a bottleneck in Tensorflow; for reasonable sizes, PyTorch is 1000x faster.

* trackbacks are easy to follow (because defines graph by running)

* it’s as fast as tensorflow [2] (or at least torch is, which calls the same C functions as PyTorch, and there’s a tweet [4] by a core dev saying to expect the same speeds). Plus on the web I’ve only found anecdotes that support PyTorch faster than tensorflow.

* it’s easy to extend; everything is a simple Python class. e.g., see their different optimizers [3]

[1] http://stsievert.com/blog/2017/09/07/pytorch/

[2] https://github.com/soumith/convnet-benchmarks

[3] https://github.com/pytorch/pytorch/tree/master/torch/optim

[4] https://twitter.com/soumithchintala/status/83545486710789734...

Privacy 9 years ago

I work with data scientists and it’s scary how much they have access to.

One first hand story: this person searched a database to find tax records for a specific individual and their income. The records were de-anonymized but there’s enough data there he could figure it out.

We should design systems to preserve individual privacy. The person I heard the story from had no business in this persons tax records.

I'm excited for self-driving cars and ML/AI tools that help professionals (e.g., drug discovery, treatment).

The Keras lead developer wrote a post called "The future of deep learning"[1]. The podcast Partially Derivative has a good summary of it[2].

On the implementation side, I'm looking forward to distribution. Computers are all around us, sitting by idly – how can we put them to use? How can we make them secure? We're starting to see integration of ML models into mobile systems (with Apple's .mlmodel and ARKit).

[1] https://blog.keras.io/the-future-of-deep-learning.html

[2] http://partiallyderivative.com/podcast/2017/07/25/the_future...

[3] http://papers.nips.cc/paper/4390-hogwild-a-lock-free-approac...

It appears the largest benefits is embedding Lua code into TeX (found at [1] in "Programmability").

The example they present from that page:

    \documentclass{article}
    \usepackage{luacode}
    \begin{document}
    \pagestyle{empty}
    \begin{luacode*}
      function esn (n)
        return (1 + 1/n)^n
      end
      function etn (n)
        tex.print(string.format('%5d & %1.8f \\\\', n, esn(n)))
      end
    \end{luacode*}

    Convergence to $e$:

    \begin{tabular}{ll}
    \rule[-2mm]{0pt}{4mm}$n$ & $(1 + \frac{1}{n})^n$ \\
    \hline
    \luadirect{
      for n = 10, 110, 10 do
        tex.print(etn(n))
      end
    }
    \hline
    \end{tabular}

    \end{document}
which allows a pretty table to be printed in the document.