
LIGO Gravitational Wave Data in iPython Jupyter Notebooks - Mizza
https://losc.ligo.org/s/events/GW150914/GW150914_tutorial.html
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Mizza
If you liked this, you may like this surprisingly fascinating talk on the
color scheme in Matplotlib used in this paper:
[https://www.youtube.com/watch?v=xAoljeRJ3lU&feature=youtu.be](https://www.youtube.com/watch?v=xAoljeRJ3lU&feature=youtu.be)

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cscheid
This talk is great! And if you watched it all the way to the 6:30 mark, where
he says "you can't have negative amounts of light", then you'll _really_ enjoy
chimerical colors:
[https://en.wikipedia.org/wiki/Impossible_color](https://en.wikipedia.org/wiki/Impossible_color)

The trick is you exploit retinal fatigue in order to perceive colors both
"above 100%" and "below 0%". Wild stuff.

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Xcelerate
As someone who keeps getting comments about my "weird" toolkit for doing
scientific research (Jupyter/Julia), this made my day.

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gaur
What would people rather have you use? Excel?

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joshvm
You would be surprised at the number of Excel plots in the literature.

Most astrophysicists use IDL or IRAF, I've never seen anyone use Matlab. The
benefits are tons of functions specifically tailored for astro data analysis.
Python is gathering momentum though, there are libraries like sunpy and
astropy. Plenty of IDL fanatics are floored when you can show them just how
easy it is to process data with the Numpy stack.

I'm _not_ an astrophysicist, but I work with a lot of them. I use Jupyter
notebook daily. It's the perfect balance between REPL python and standalone
scripts. My typical workflow is to hack something together in a notebook,
which lets you iterate very quickly, then once I'm happy I freeze the code
into a module.

~~~
gaur
Haha, I forgot about IDL. My very first coding project as an undergrad was in
IDL, until one day a new grad student showed up to the lab and said, "WTF? Do
this in python."

When looking at plots in papers, there are always little giveaways for what
program it was made in. Plot has horizontal gridlines, but no vertical
gridlines: Excel. Plot is typeset with Arial, size 4: Matlab. Plot looks like
it was sent through a fax a few times: IDL.

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cdelsolar
Did the LIGO paper use matplotlib? I thought it did but that would be too
cool.

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wiz21
Donald Knuth is probably swimming in joy right now. This so literate
programming (or should I say literate research)...

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po84
[https://github.com/minrk/ligo-binder](https://github.com/minrk/ligo-binder)

Re-run the analysis yourself on Jupyter using Binder. Click the launch binder
button.

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qhoc
Just curious on binder specific here. I could never got it to work out-of-the-
box. In this example, it gave me "ImportError: No module named 'seaborn'"
error. Now I could do something like !sudo pip install seaborn but still...
Did you guys have same experience?

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anotheryou
can anyone tell me how the figured out where the black holes are?

with just 2 "ears" I'd expect to be only able to determen a circle, but here
is the picture they released:
[http://content.screencast.com/users/cougarten/folders/Jing/m...](http://content.screencast.com/users/cougarten/folders/Jing/media/64d98a70-7b90-45b6-ac97-2518aa657171/2016-02-11_1650.png)

Do i see a warped circle, or the bottom part of one? In the latter case I
wonder how they found out.

Are the L-shape sensors capable of seeing some direction depending on which
way the phases shift first/last?

If you'd build one of the sensors in reverse you'd see a reversed signal, no?
Given that they will have optimized the orientations of both stations this is
probably how it worked and I'm seeing just part of a circle, right? That one
lonely blob might be an unlikely mirrored version.

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ck2
For a moment I thought "notebook" meant like laptop.

And I was like, wow that is amazing, they crowdsourced data from all over the
world.

Then I remembered the sensitivity of the instruments used and how dumb I was.

But it really would be cool if oneday people had smartphones so advanced they
could contribute to worldwide collection of data that needed a huge area to
sample. I think they are talking about doing that for earthquake alerts.

~~~
madvoid
WeatherSignal is doing something along those lines for weather data:
[http://weathersignal.com/about/](http://weathersignal.com/about/) I'm excited
to see where this kind of tech goes.

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melted
Makes for a nice demo of Python Notebook capabilities, especially when it
comes to graphing.

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jeffjose
As a python fanboy this makes me really happy. Great job, folks at PSF and
Jupyter

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daveguy
Note the sample code is in Python 2.7 _not_ 3.x. In general you should avoid
3.x for scientific computing as it is slower and less supported in academia.

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erispoe
That's interesting, do you have a good source on that? I switched to 3.x for
development but I do academic projects too.

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joshvm
I don't know about speed, most of the modules where speed matters, like Numpy,
rely on calling C routines somewhere down the line. The version of Python
shouldn't make a significant difference.

Numpy, Scipy and Pandas work with Python 3, Jupyter certainly does. That
covers probably 80% of scientific grunt work. For specialist applications,
OpenCV 3.0 works, as does scikit-learn/image. I can't speak for other
development like web though.

I think the main problem is that if you're using someone else's code in
academia, it's likely to be written in 2.7 and you would have to go through
and update everything that's not back-compatible.

