3 ms·

I'm sorry, but I don't see any much use in this visualization. It's pretty, but gives almost no information at the global level, for two reasons: 1) It's not a

by BoppreH 12y ago

I'm sorry, but I don't see any much use in this visualization. It's pretty, but gives almost no information at the global level, for two reasons: 1) It's not adjusted for population ( http://xkcd.com/1138/ http://xkcd.com/1138/ ). They can normalize the data to fix this. 2) The map is ludicrously distorted because of the Mercator projection. Greenland looks bigger than the entire South America, when it should be an eighth of the size. This directly affects the perceived density in each area. Suggestion: if you are using an interactive geographical visualization, why not display a globe? However, it does look stunning.

BoppreH 12y ago
By the way, West Wing had an excellent piece where they explain the need for accurate map projections: https://www.youtube.com/watch?v=n8zBC2dvERM https://www.youtube.com/watch?v=n8zBC2dvERM
maxerickson 12y ago
There is no claim that the density means anything, so there isn't any need to adjust it for population. I imagine the title "OpenStreetMap node density map 2014" was somewhat carefully chosen, and it manages to say what is shown. If you read the link that Vik1ng posted, the author seems to be fairly clear that they were just making a pretty picture (and quietly points out the problems with the projection).
- BoppreH 12y ago
  Density here is number of nodes by area, and if you distort the area it stops being density. It's like comparing the weight of different objects on different planets. "My shoe on Earth weights twice as much as my sandal on Saturn" isn't very useful. And thanks for mentioning the link, but I don't see where they say it was made for a pretty picture.
  - maxerickson 12y ago
    Yes, I said "seems to be" to suggest that it was my impression of the page, rather than a quote from it or whatever. Part of that impression is that you can't really zoom in far enough to do anything super useful with it, so it's probably just to look at.
Vik1ng 12y ago
@1 I think the main goal is simply to display OpenStreetMap node density. Nothing more and nothing less. For mappers it's kinda interesting. He did't want to make a map where the most active mappers are.
- BoppreH 12y ago
  But if it's the same as a population map, what good is it? If I had asked you about nodes density before you saw this picture, your guess would probably use the population density. If your guess remains the same after seeing the picture, it didn't give you any useful information. I think this is gorgeous, and the process of making a visualization is interesting, but I'm questioning the usefulness of the information portrayed.
  - yellowbkpk 12y ago
    But it isn't just a population map. You can see where users have imported data (e.g. the parts of Canada that are lit up in small squares is CANVEC data) and you can see the relative brightness of the map in Europe vs. United States -- even in areas of higher population density the US is dimmer than most of Europe because there are more mappers there.
    - BoppreH 12y ago
      I hadn't noticed the small squares before. I stand corrected in that front, that is useful. But on the Europe vs USA case note how you are automatically adjusting for population. Because of this you can only interpret data for places you know the demographics, and even that is error prone.
  - rakoo 12y ago
    > I'm questioning the usefulness of the information portrayed It does give you information on which parts of the world are more active in the project: the 3 biggest economic regions are the more mapped regions. Besides, does everything need to be useful ?
laurent123456 12y ago
That what I thought at first but the visualization is actually useful. For instance, I have the offline OpenStreet map of Germany on my phone, which is about 1GB. In comparison, the map China is about 110MB, despite having a population 15 times bigger. The node density map does actually reflect this kind of differences. I find the difference between Brazil, Chile and Argentina also quite interesting.

by BoppreH 12y ago

BoppreH 12y ago

By the way, West Wing had an excellent piece where they explain the need for accurate map projections: https://www.youtube.com/watch?v=n8zBC2dvERM https://www.youtube.com/watch?v=n8zBC2dvERM

maxerickson 12y ago

There is no claim that the density means anything, so there isn't any need to adjust it for population. I imagine the title "OpenStreetMap node density map 2014" was somewhat carefully chosen, and it manages to say what is shown. If you read the link that Vik1ng posted, the author seems to be fairly clear that they were just making a pretty picture (and quietly points out the problems with the projection).

BoppreH 12y ago
Density here is number of nodes by area, and if you distort the area it stops being density. It's like comparing the weight of different objects on different planets. "My shoe on Earth weights twice as much as my sandal on Saturn" isn't very useful. And thanks for mentioning the link, but I don't see where they say it was made for a pretty picture.
- maxerickson 12y ago
  Yes, I said "seems to be" to suggest that it was my impression of the page, rather than a quote from it or whatever. Part of that impression is that you can't really zoom in far enough to do anything super useful with it, so it's probably just to look at.

Vik1ng 12y ago

@1 I think the main goal is simply to display OpenStreetMap node density. Nothing more and nothing less. For mappers it's kinda interesting. He did't want to make a map where the most active mappers are.

BoppreH 12y ago
But if it's the same as a population map, what good is it? If I had asked you about nodes density before you saw this picture, your guess would probably use the population density. If your guess remains the same after seeing the picture, it didn't give you any useful information. I think this is gorgeous, and the process of making a visualization is interesting, but I'm questioning the usefulness of the information portrayed.
- yellowbkpk 12y ago
  But it isn't just a population map. You can see where users have imported data (e.g. the parts of Canada that are lit up in small squares is CANVEC data) and you can see the relative brightness of the map in Europe vs. United States -- even in areas of higher population density the US is dimmer than most of Europe because there are more mappers there.
  - BoppreH 12y ago
    I hadn't noticed the small squares before. I stand corrected in that front, that is useful. But on the Europe vs USA case note how you are automatically adjusting for population. Because of this you can only interpret data for places you know the demographics, and even that is error prone.
- rakoo 12y ago
  > I'm questioning the usefulness of the information portrayed It does give you information on which parts of the world are more active in the project: the 3 biggest economic regions are the more mapped regions. Besides, does everything need to be useful ?

laurent123456 12y ago

That what I thought at first but the visualization is actually useful. For instance, I have the offline OpenStreet map of Germany on my phone, which is about 1GB. In comparison, the map China is about 110MB, despite having a population 15 times bigger. The node density map does actually reflect this kind of differences. I find the difference between Brazil, Chile and Argentina also quite interesting.