OpenStreetMap

pnorman has commented on the following diary entries

Post When Comment
Is Vancouver's SkyTrain a subway? 6 days ago

The SkyTrain is a railway=subway as defined in OSM. As the text usually underground indicates, most railway=subway systems are underground, but this one isn't for much of the length.

The Evergreen line was originally planned to be light rail, but was changed to use the same technology as Skytrain. There are also tentative plans for light rail sometime in Surrey

Making a multilingual map of India using OpenStreetMap data 3 months ago

Can't really recommend one over the other since I have not tried generating vector tiles myself. My guess is that the standard osm2pgsql/postgres setup should work.

That's a database setup, not a vector tile setup. The issue isn't the software, but the source definitions.

Making a multilingual map of India using OpenStreetMap data 3 months ago

pnorman, the first step is to create vector tiles of the data you want to render. One can do this from a regular mapnik source using https://github.com/mapbox/tilelive-bridge .

What Mapnik source do you recommend to generate vector tiles with so that the tiles will work with the work you describe in this post?

Making a multilingual map of India using OpenStreetMap data 3 months ago

It's good to see native language rendering.

One question is if someone wanted to reproduce this themselves without relying on third-party services, is there any way, or is it tied into components which can't be reproduced like the Mapbox Streets vector tile set?

Field Mapping Setup 3 months ago

Are you using the Garmin Virb X or XE? I've found GPS problems when taking photos with the XE at a 2 second interval, how often do you take them?

African Roads and a Western Bias in Mapping 3 months ago

highway=track isn't about road surface and never has been. Unfortunately, some people use it for unpaved roads, which is wrong, and leads to these problems.

Is there possibility to retag addr:housenumbers without european scheme? (updated) 4 months ago

I regularly tag 5-digit addresses with the Karlsruhe schema for addresses and it works fine. There are no problems with addresses that jump by large numbers when there is a crossing street.

Updated contributor stats 6 months ago

The last few years have had drops around end of year/start of year, but this one is about twice the absolute size of previous drops.

OpenStreetMap active users 6 months ago

Ideally such stats should also include users who contributed only in changeset discussions and with notes - it would be especially interesting to know if these are primarily a domain of otherwise active mappers or if there is a distinct group of users who primarily engage in discussion only and do not perform edits themselves.

I've got the discussion data in the same DB, so it would be easy to run. My impression is that discussions won't make a big difference, but there are more note-only contributors. Unfortunately, I don't have notes in a PostgreSQL DB so can't check this.

Paul did you remove zero-edit changesets?

No. I'd have actually preferred to generate a graph based on user logins or other activity, but for obvious reasons this isn't possible.

In principle although the choice of a 30 days window is perfectly reasonable as a you have to pick one solution it would be nice to have a more detailed spectrum of the contributor activity w.r.t. frequency

Using custom Mapbox layers for mapping missing features in JOSM 6 months ago

I'd suggest using tms[19] instead of tms[99]. You don't want JOSM to request the imagery for silly-high zoom levels.

How large are our national contributor communities and how are they developing? 7 months ago

I'd be interested in how the growth of active contributors is per country. This is influenced by both the rate that people join, and the rate they leave. There's a few ways to define an active contributor, but the contributor terms includes a reasonable one

a natural person (whether using a single or multiple accounts) who has edited the Project in any three calendar months from the last 12 months [and is contactable for a request to vote]

We can't easily look at a natural person, but having changesets in at least three months over the last 12 months is the type of criteria that's easily evaluated.

Overall, the growth is linear in the last few years

More specifically, it's 232 additional active contributors per month, R^2=0.996.

The problem I had when I tried to break it down was

  • People who are active contributors overall, but not in any one country
  • People who are active contributors in multiple countries
  • Migration of mappers

Maybe these don't matter and you could just use current location estimates for each active mapper, and then break down the list each month.

OpenStreetMap Carto Complexity 7 months ago

In addition to Mapbox Streets there are also other styles that use preprocessing. Like OpenTopoMap

I hadn't counted those lines, but there's only about 50 there. And of those, only about 10 lines seem to be ones you should run, the rest are a SQL statement that doesn't seem to do anything.

CartoDB basemaps also use some preprocessing, but not trigger-based like Mapbox streets.

3k lines of preprocessing triggers and other SQL is, in my experience, unique.

In fact you could say through the coastlines all styles make some use of external data preprocessing that is based on additional code

None of them are maintaining their own coastline code, except perhaps to import coastlines into PostgreSQL. I think I counted it where they're doing that but shouldn't have, because I didn't count osm-carto get-shapfiles.sh which is also probably longer than other styles.

Quite a lot of the code complexity in osm-carto is there to work around limitations of the capabilities of the software used

All the styles use PostgreSQL, PostGIS, and Mapnik. I don't think any of them are making any assumptions about versions, unless they happen to create databases and use the CREATE EXTENSION syntax. I guess some of the CartoCSS styles would also work with Mapserver and magnacarto instead of Mapnik and carto, but no one is targeting that.

many styles use external non-osm data which often essentially means externalizing processing complexity

With the possible exception of CartoDB, they're not editing the external sources. If they don't have to edit them, it doesn't add to the maintenance burden.

Quantifying HOT participation inequality: it's complicated. 8 months ago

I think referring to the workload spread as "unfair" is misleading. "Inequality", although probably correct from a statistics point of view, is also a word that is associated with discrimination.

I'm not surprised to see power-law distributions. When I looked at overall contributor stats, changeset size, API reply size and several other measures, I saw power laws coming up.

Use Grass&Green and enhance the data classification 9 months ago

So, it's basically an editor that just shows you only features with some natural and similar tags?

It's interesting to call forest grass-covered, since neither natural=wood or landuse=forest implies the presence of grass.

Improving the OSM Map - why don't we? [11] 9 months ago

Neighborhood has a formal administrative meaning.

The place tags are for geographic places, not administrative divisions. Sometimes these are the same, sometimes not. For example, a town nearby, Langley, is composed of part of the City of Langley and Township of Langley, which are both administratively cities. A mistake that sometimes happens in the US is to call any incorporated area a place=city.

If we wanted to avoid using British English in tags, we could encode all tags as arbitrary numbers or strings. Except, to someone not working in English, that's already what we do, because they should see a translation for the presets.

Harry Wood admin abuse. Do we need him as admin at wiki??? 10 months ago

I truly believe that my edits were slowly improving content and they are supported

With repeated requests to permanently ban you after your 3 month ban expired, this is clearly not the view of many others.

Postigs question - find out the unnecessary points that exist on the map 10 months ago

Doing a way simplification with a threshold of 0 is unlikely yield any practical speed improvements.

It takes about one to two days to import the planet with osm2pgsql, assuming reasonable hardware. The node parsing stage takes about 15 minutes. It's unlikely to speed up multipolygon-related computations, the slowest part of the import. It won't speed up clustering or rendering table index creation.

My guess is that there would be no detectable speed increase.

How many days or weeks does it take to upload the whole planet via Osmosis ? 10 months ago

What area did you use for testing your command, and how long did it take?

Did you load in either the linestring or bbox columns?

What speed drives do you have?

exit_to vs destination (USA) 10 months ago

What would be interesting is counts of exit_to without destination and destination without exit_to.

But harder to query.

What do maps mean to us? 10 months ago

To see what people would map themselves, we can look at how mapping has progressed in OSM, and how mapping progresses as a new area puts itself on the map without distortions from imports or organized non-local mapping.

From this, we can see residential areas (landuse=residential) and comprehensive building coverage are some of the lowest priorities, but these are regularly the main focus of humanitarian mapping.