Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

World Airports Voronoi

jasondavies.com

Post reply on HN
Print view View original

71–80 of 90 posts

Re: World Airports Voronoi

#71

Post by golergka »

jacobolus wrote: post #51
golergka wrote: post #6

This runs slower on my computer than MGSV in ultra settings running on 4k resolution.

It’s projecting thousands of sphere geodesics at pixel precision via breaking them into a large number (hundreds of thousands?) of little line segments and evaluating several expensive nonlinear functions at each of those points with considerable Javascript dataflow overhead for each one, not to mention the cost of putting thousands of polygons with dozens or hundreds of points each into SVG. It would take either a d…

It runs Voronoi every step instead of building polygons once?

Why?

Re: World Airports Voronoi

#72

Post by simonbyrne »

slake wrote: post #62

This is really cool. If I remember right international passenger flight regulations insist that there be atleast one airport that can handle your class of aircraft within 180 minutes of flying time at one engine operative speeds at all times. If we assume a passenger jet flies at roughly 0.8 Mach or ~960 kph, and one-engine operative speed is roughly 40% of that or ~384 KPH. That means an airport needs to be within a…

I believe that's only true for 2 engine aircraft.

Virgin Australia briefly ran a service from Melbourne to Johannesburg using 777s, which was 2 hours longer than it needed to be for this reason. Looking at this map, it's clear why: the great circle path almost goes over Antarctica, and the closest airports over the path are in Australia and South Africa.

Re: World Airports Voronoi

#73

Post by idlewords »

minimax wrote: post #45
idlewords wrote: post #31

What a cool project! This is very fun to play with in conjunction with the ETOPS (extended twin-engine operations) settings on the Great Circle Mapper. http://www.gcmap.com Among other things it drives home how remote the waters MH370 disappeared in are.

I recently did ORD-HKG and spent quite a lot of time thinking about ETOPS diversion airports over Siberia (because honestly what else are you gonna do). Now I'm wondering if you can even land a fully laden 777 at any of them. Most of them don't even seem to have wikipedia pages.

I suspect there's a lot of places in Siberia where you can land a 777 just fine. It's the amenities in the terminal building (if there is one) that won't be too appealing.

In Soviet times, a lot of civil infrastructrure was built with an eye to military use, so you get some suspiciously long runways at rinky-dink airports.

Re: World Airports Voronoi

#74

Post by dingaling »

slake wrote: post #62

This is really cool. If I remember right international passenger flight regulations insist that there be atleast one airport that can handle your class of aircraft within 180 minutes of flying time at one engine operative speeds at all times. If we assume a passenger jet flies at roughly 0.8 Mach or ~960 kph, and one-engine operative speed is roughly 40% of that or ~384 KPH. That means an airport needs to be within a…

ETOPS clearance has now reached 330 minutes for the latest aircraft types

http://boeing.mediaroom.com/2014-05-28-Boeing-Receives-330-M...

ETOPS also now applies to new-build quads.

"Regulation 14 CFR 121.161 requires four-engine passenger airplanes built after February 2015 to observe ETOPS if the flight route is more than 180 minutes (3 hours)"

Re: World Airports Voronoi

#75

Post by [deleted] »

simonbyrne wrote: post #72
slake wrote: post #62

This is really cool. If I remember right international passenger flight regulations insist that there be atleast one airport that can handle your class of aircraft within 180 minutes of flying time at one engine operative speeds at all times. If we assume a passenger jet flies at roughly 0.8 Mach or ~960 kph, and one-engine operative speed is roughly 40% of that or ~384 KPH. That means an airport needs to be within a…

I believe that's only true for 2 engine aircraft. Virgin Australia briefly ran a service from Melbourne to Johannesburg using 777s, which was 2 hours longer than it needed to be for this reason. Looking at this map, it's clear why: the great circle path almost goes over Antarctica, and the closest airports over the path are in Australia and South Africa.

[deleted]

Re: World Airports Voronoi

#76

Post by jacobolus »

golergka wrote: post #71
jacobolus wrote: post #51

Earlier quoted context omitted.

It’s projecting thousands of sphere geodesics at pixel precision via breaking them into a large number (hundreds of thousands?) of little line segments and evaluating several expensive nonlinear functions at each of those points with considerable Javascript dataflow overhead for each one, not to mention the cost of putting thousands of polygons with dozens or hundreds of points each into SVG. It would take either a d…

It runs Voronoi every step instead of building polygons once? Why?

No it does not. Computing the spherical polygons that make up the Voronoi diagram just happens once.

The expensive part is rendering them in an arbitrary map projection.

Considering this is an orthographic projection, and therefore spherical polygon edges are all ellipses, rendering this picture could certainly be special-cased to only draw ellipses and thereby run much faster. But it’s using a very general D3-geo framework. If you want you can easily tweak the code and the map will be drawn on whatever projection you like.

To see some of the possibilities, go to http://bl.ocks.org/mbostock and scroll down a bit.

Re: World Airports Voronoi

#77

Post by 13hours »

As a South African, I never realised we have a few airports that are actually the closest to a large part of the Antarctic coast. I know there are flights from Chile and New Zealand to Antarctica, but none that I'm aware of from South Africa.

Re: World Airports Voronoi

#78

Post by dagw »

forrestthewoods wrote: post #39
golergka wrote: post #6

This runs slower on my computer than MGSV in ultra settings running on 4k resolution.

Completely unusable on my iPad Air. Damn. It's amazing how fast computers are. And it's amazing how slow we make them with layers and layers of cruft built atop more layers and layers of cruft.

Without those layers of 'cruft' putting together something like this would involve weeks of work by a team of domain experts, rather than a few hours of work by a single person in his free time.

Re: World Airports Voronoi

#79

Post by Arnt »

Xophmeister wrote: post #44
teraflop wrote: post #35

Pretty soon there's going to be a nice big new polygon added in the middle of the South Atlantic: https://en.wikipedia.org/wiki/Saint_Helena_Airport

Looking at the map, I am liking some of the place names on St. Helena; "The Gates of Chaos" is a particular favourite.

Something tells me you'll like the noun the inhabitants use for themselves. Hint: They don't call themselves "helens".

Re: World Airports Voronoi

#80

Post by ygra »

andrepd wrote: post #46
golergka wrote: post #6

This runs slower on my computer than MGSV in ultra settings running on 4k resolution.

I know right?? It's mind-blowing! My PC can push millions (is that the order of magnitude?) of polygons per second. But it locks up an entire core to render a couple hundred polygons (plus the layers of cruft), and can't do it at more than ~10Hz.

Rendering isn't the slow part here. The projection is (and map projections are quite expensive to calculate).
Post reply on HN