
The relativistic discriminator: a key element missing from standard GAN - neuhaus
https://ajolicoeur.wordpress.com/RelativisticGAN/
======
Y_Y
This is just confusing misuse of the word "relativistic", being based as it is
on _relative_ probability and having little to do with philosophical
relativism and nothing to do with physics relativity.

~~~
AlexiaJM
"Relative probability" is only correct for standard GAN, not for other GANs
which don't estimate a probability.

My first name was "Critic's difference" since it's literally C(x_r)-C(x_f) so
its the difference in critics, but it felt really unclear, it doesn't give the
reader any sense of what it is about. Relativism/Relativistic is better since
it's to say that it really doesn't matter if the data looks real, what matters
if how realistic is real data relative to fake data (and vice versa). The
frame of reference is important here.

~~~
radarsat1
It's not even probability in standard GAN is it? Since you are taking the
difference before the sigmoid. It can't really be interpreted as probability
until it the range is clamped. Critic's difference or Critical Difference
would be a better term perhaps.

~~~
sophistication
It's logits or log odds or the logarithm of the odds, i.e. log(odds(p)) =
log(p / (1 - p)):
[https://en.wikipedia.org/wiki/Logit](https://en.wikipedia.org/wiki/Logit)

Since sigmoid(C(x_r)) = p(x_r is real) and C(x_f) = p(x_f is real), the
sigmoid of the difference expresses some probability that that x_r looks _more
real_ than x_f or vice versa (depending on whether it is C(x_r) - C(x_f) or
C(x_f) - C(x_r)). Not sure whether there is a probabilistic interpretation of
the difference, but it looks so simple that there maybe is one. I couldn't
find one in the paper.

~~~
sophistication
Correction: sigmoid(C(x_f)) = p(x_f is real)

------
rmgraham
GAN, Generative Adversarial Network:
[https://en.wikipedia.org/wiki/Generative_adversarial_network](https://en.wikipedia.org/wiki/Generative_adversarial_network)

------
anonfunction
Same guy who wrote this has another post called Deep learning with cats[1]
which has a great open source repo[2] with multiple GANs.

1\.
[https://ajolicoeur.wordpress.com/cats/](https://ajolicoeur.wordpress.com/cats/)

2\. [https://github.com/AlexiaJM/Deep-learning-with-
cats](https://github.com/AlexiaJM/Deep-learning-with-cats)

~~~
shrubhub
Same guy? Try... Not a guy!

~~~
anonfunction
Thanks for correcting me! I commonly call a group of people "guys" even if
they are women, this is something I need to break the habit of. Will strive to
be gender neutral in the future.

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DanielleMolloy
Interesting, especially the performance on bigger images, and it looks like a
low-effort modification of many standard GAN losses. Seriously, I want to give
this a try right now. What do GAN researchers think about this paper?

It should also be appreciated that it comes with code _and_ a short blog post.

~~~
radarsat1
And a 24-page paper ;)

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dang
Since the url is the same we changed the title to the one the author had for
[https://news.ycombinator.com/item?id=17449143](https://news.ycombinator.com/item?id=17449143).

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xstephen95x
what 'computer scientist' uses wordpress for their blog. Though, I don't have
a blog, so...

~~~
tzs
Dick Lipton and Ken Regan, for example:
[https://rjlipton.wordpress.com/](https://rjlipton.wordpress.com/)

Scott Aaronson:
[https://www.scottaaronson.com/blog/](https://www.scottaaronson.com/blog/)

Jeremy Kun: [https://jeremykun.com/](https://jeremykun.com/)

Also, although he's a mathematician rather than a computer scientist, there is
Terry Tao: [https://terrytao.wordpress.com/](https://terrytao.wordpress.com/)

~~~
anonfunction
Wonder what he thinks (not really) of Rob Pike using blogspot:
[https://commandcenter.blogspot.com/](https://commandcenter.blogspot.com/)

