
Why Topological Data Analysis Works - psoto
http://www.ayasdi.com/blog/bigdata/why-topological-data-analysis-works/
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devilsdounut
I'd love to see a success story of this type of analysis outside of their
canned examples. I keep seeing them use the same datasets over and over again
without any real benchmarks to state of the art. Its amazing how a data
product is being sold without any empirical studies or benchmark datasets.

Ayasdi seems successful to me in that it has a lot of flash and their results
make intuitive sense, but I don't understand how a practicing data scientist
would use this.

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cvsv
I've seen it used "in the wild" in this publication: "Topographical
transcriptome mapping of the mouse medial ganglionic eminence by spatially
resolved RNA-seq"
[http://genomebiology.com/2014/15/10/486/abstract](http://genomebiology.com/2014/15/10/486/abstract)
(pdf:
[http://linnarssonlab.org/pdf/Genome%20Biology%202014.pdf](http://linnarssonlab.org/pdf/Genome%20Biology%202014.pdf)
) to cluster gene expression samples from mouse brain.

I'm working on a project where I'm using similar methods, but not from Ayasdi,
to study cyclic phenomena in high-dimensional data.

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devilsdounut
Ok, so here it's used to cluster. There are tons of benchmark clustering
datasets. Never seen it used on any of those.

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fizixer
The key paragraph "The projection is visualized as ... pictured as below." is
very ambiguous, and completely missing the explanation of how the data was
split into red, blue, and indigo clusters.

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IndianAstronaut
Isn't response surface methodology a form of topological data analysis? IIRC,
it isn't used much since it has poor predictive power.

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avani
The key with Ayasdi's work is that they manage to layer the TDA with different
ML filters, which does stunningly well for the datasets they like talking
about.

I also second the notion to read papers from the Carlsson lab, particularly
one of the more application-oriented papers such as this one:
[http://www.nature.com/srep/2013/130207/srep01236/pdf/srep012...](http://www.nature.com/srep/2013/130207/srep01236/pdf/srep01236.pdf)

