The largest city in each 10x10 degree latitude/longitude box • Hacker News Board

Re: The largest city in each 10x10 degree latitude/longitude box

#41

Post by chrisseaton » Thu, Jun 25, 2020, 12:57 PM UTC

NopeNotToday wrote: post #32

caf wrote: post #25

I quibble with the description of the shapes bounded by 10 degrees of longitude and latitude as "rectangles" - they're not even planar shapes, and their adjacent sides certainly aren't at right angles. Some of them don't even have four sides. This bears considering when looking at the map, because some of those regions are much, much smaller than others.

He's not making a mathematical definition of the areas. 'area' or 'box' is a simple description that everyone can understand. And the map projection used does form squares.

> And the map projection used does form squares.

Some of those squares have zero-length edges.

Re: The largest city in each 10x10 degree latitude/longitude box

#42

Post by AMerrit » Thu, Jun 25, 2020, 12:59 PM UTC

cosminratiu wrote: post #27

pretendgeneer wrote: post #5

I was surprised by Leonora, Western Australia being there with it's population of 556 [1], I tried to find a bigger town in the area but couldn't. I wonder if that is the smallest town on that map? [1] https://en.wikipedia.org/wiki/Leonora,_Western_Australia

Alert in northern Canada has 62 permanent inhabitants, according to wikipedia [1] [1] https://en.wikipedia.org/wiki/Alert,_Nunavut

I had a friend who worked up in Alert while he was in the air force. It may be one of the most remote places on the map, it's essentially an out grown air force base/research station, there would be nothing there if not for the cold war.

Re: The largest city in each 10x10 degree latitude/longitude box

#43

Post by ewendel » Thu, Jun 25, 2020, 1:03 PM UTC

toxik wrote: post #39

incompatible wrote: post #26

Earlier quoted context omitted.

A map projection that preserves area would be better, otherwise there's an excessive number of cities in the far northern hemisphere, and a lack of detail in the tropics.

Meanwhile, neither Sweden’s nor Norway’s capital is in the map. But two smaller Norwegian cities are. I think this just teaches you the issue with discretization.

There are in fact five small Norwegian towns on this map.

Vadsø, Hammerfest, Trondheim, Bergen and Longyearbyen.

Re: The largest city in each 10x10 degree latitude/longitude box

#44

Post by Tempest1981 » Thu, Jun 25, 2020, 1:04 PM UTC

incompatible wrote: post #26

foota wrote: post #19

I think something more interesting might be like a voronoi diagram of all cities such that the city is in like the top 5 within a 1000 miles radius or something (or just that but without the voronoi part). This should preserve the fact that only the largest cities in some area are present, but eliminate the arbitrariness of the boundaries. I think you would want to compute this with a sweep line algorithm.

A map projection that preserves area would be better, otherwise there's an excessive number of cities in the far northern hemisphere, and a lack of detail in the tropics.

I like xkcd's description of Mercator: https://xkcd.com/977/

Re: The largest city in each 10x10 degree latitude/longitude box

#45

Post by ghaff » Thu, Jun 25, 2020, 1:05 PM UTC

mc32 wrote: post #20

horsawlarway wrote: post #10

Earlier quoted context omitted.

a lot these are pretty bad representations of real population, even in the US. ex: Jacksonville is listed as the largest city in the southeast, and strictly speaking, this is true because it's a fairly dense population area. But it's a pretty misleading statement to say that it's the largest city. Jacksonville's metro population is only about 1.5 million. Atlanta is in the same box and Atlanta's metro population is n…

To me that’s not misleading in that they count city proper rather than metro areas. Both have their places, but I wouldn’t say one is more misleading than the other. One is administrative and one is more demographic.

And they both go to show that statements/calculations about things like urban density are heavily influenced by historically and culturally determined political boundaries and definitions. Even look at the US Census Bureau 80% urban metric that a lot of people like to quote. Lots of small towns with farmlands and orchards (like where I live) are "urban" by this particular definition. And they are "urban" relative to truly rural Wyoming. But they're not urban in the sense of having any of the attributes of a dense city center.

Re: The largest city in each 10x10 degree latitude/longitude box

#46

Post by hellofunk » Thu, Jun 25, 2020, 1:08 PM UTC

griffinkelly wrote: post #40

allengeorge wrote: post #16

I’m fairly sure Toronto is larger than Chicago... EDIT: Yeah, back in 2013: https://www.thestar.com/news/city_hall/2013/03/05/torontos_p... - and I’m pretty sure it’s almost at or crossed the 3M mark (COVID may have tossed a wrench in the latter). Ah. It’s because Toronto is in the same box as _New York_ - my bad!

Chicago is having significant population loss, so that gap will only grow. I believe Houston is about to pass Chicago.

Why is Chicago losing people?

Re: The largest city in each 10x10 degree latitude/longitude box

#47

Post by jl6 » Thu, Jun 25, 2020, 1:10 PM UTC

I wonder if London could be the largest city in two boxes. The zero meridian line goes through Greenwich, which leaves most of London in the western box, but a still sizeable chunk of East London in the eastern box.

Is East London bigger than Hamburg?

Are there any other large cities that straddle the bounding boxes?

Re: The largest city in each 10x10 degree latitude/longitude box

#48

Post by baud147258 » Thu, Jun 25, 2020, 1:13 PM UTC

There's a typo in Port-aux-Français, the name on the map is missing an x.

Re: The largest city in each 10x10 degree latitude/longitude box

#49

Post by sdflhasjd » Thu, Jun 25, 2020, 1:23 PM UTC

jl6 wrote: post #47

I wonder if London could be the largest city in two boxes. The zero meridian line goes through Greenwich, which leaves most of London in the western box, but a still sizeable chunk of East London in the eastern box. Is East London bigger than Hamburg? Are there any other large cities that straddle the bounding boxes?

And Hamburg at 10°E is also split, so really the question is: Is East London bigger than West Hamburg

Re: The largest city in each 10x10 degree latitude/longitude box

#50

Post by hpkuarg » Thu, Jun 25, 2020, 1:30 PM UTC

ghaff wrote: post #45

mc32 wrote: post #20

Earlier quoted context omitted.

To me that’s not misleading in that they count city proper rather than metro areas. Both have their places, but I wouldn’t say one is more misleading than the other. One is administrative and one is more demographic.

And they both go to show that statements/calculations about things like urban density are heavily influenced by historically and culturally determined political boundaries and definitions. Even look at the US Census Bureau 80% urban metric that a lot of people like to quote. Lots of small towns with farmlands and orchards (like where I live) are "urban" by this particular definition. And they are "urban" relative to…

There must be a way to come up with an (almost) universally applicable metric of city-ness, regardless of the adminstrative boundaries, that can be applied to situations like this map. Something like, the area in which the population density is above a certain threshold, and the population that lives in that area.