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Comment by thesystemis | Hacker News Reader

I helped make this (with the google data arts team), happy to answer any questions about it.

also if it's helpful, there's a technical write up here: https://medium.com/@zachlieberman/land-lines-e1f88c745847#.k...

and overview video: https://www.youtube.com/watch?v=w6-LK9BOVTA

This is extremely inspiring for me. Thank you for sharing how you did it!

thanks! that's great to hear

Can you explain how you use the vantage tree? What are you storing/searching for? What error metric are you using for matching?

I think you briefly talked about using heading change and distance for encoding your polyline. So if I understand correctly, something like:

[forwardDistance1, angleDelta1, forwardDistance2, angleDelta2, ...]

Then are you using it kinda like a kd-tree (filter everything within a threshold of forwardDistance1, then angleDelta1, then next dimension and so on)? But then how do you handle the initial scaling? What about cumulative error in heading or distance?

Congrats on the amazing work by the way!

thanks! I am using a metric from the dollar gesture recognizer

http://depts.washington.edu/madlab/proj/dollar/index.html

which gives a value for how close to polylines are (it normalizes them and does some distance calculations)

the way the vp tree works is you provide a set of data and a metric for distance (in my case, the data was the polylines and the metric was from dollar) and it computes the structure. As long as the metric observes some basic principles (I think it's called triangle inequality) the spatial division will work and you can do a fast search for nearest neighbors.

How does one arrive on a data arts team? was it a passion project or was it an existing team in the org? also how would you hire for such a team? thanks.

I'm not on the data arts team (I collaborated with them on this) but I'll ping them to answer.

This was a passion project, they approached me with a set of data -- satellite images, and we discussed different ways of visualizing them, etc.

Nice (from watching the video)!

I'm on Chrome (55.0.2883.95 (64-bit)), though, and I'm getting:

"This experience requires WebGL. Please try again using a WebGL enabled browser, such as Google Chrome"

It is possible that something is disabling your WebGL support. You can check the status of your GPU support in `chrome://gpu` and, if necessary, use the "Override software rendering list" in `chrome://flags` to force it.

Thanks. That might be it.

I actually disabled hardware acceleration because of a macOS Sierra but that would keep logging me out.

Will try messing with the settings.

How do you feel about bringing back "Best viewed in Internet Explorer" for modern times?

Where are you seeing that? I don't see any browser recommendations on the page, and it works beautifully in Safari and Firefox.

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