Talk:FAQ

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Discuss the FAQ page here. Please note, if you want to ask questions there are better Contact channels to use


Suggested Additions

It would be good to have a FAQ item along the lines of 'I want to help, what can I do?' and 'If I want to get a GPS device to help, which one should I get?'. User:Rory.parore@gmail.com 22:23, 4 May 2006

How about "How can I extract raw data from the openstreetmap database?" for example "I'd like to get all the lat,long of all the placenames in Britain, how do I do that?" -- User:Djcmackay 12:24, 26 January 2008
Agreed. My own raw data query would be "all Map Features:boundary within a given rectangle." This way, i could code my own contour mapper for some countries and continents... -- Jokes Free4Me 17:11, 26 January 2010 (UTC)
Update: The About#Development section finally led me to find API and OSM Server Side Script. I hope to be able to use these soon enough. -- Jokes Free4Me 18:26, 1 February 2010 (UTC)

Internationalization

There are bugreports about missing chinese fonts, utf-8 bugs,... Zürich, Bangkok, Beijing,... are rendered wrong. I can't believe that it is not possible to repair that. What's going on? -- User:Robotnik 16:17, 29 January 2008

My GPX file uploaded with less than the total number of points!

Why is the time element required? It is not a required element in the GPX schema. I have a file of track points that I've just had to manually insert a whole lot of fake timestamps so that I could upload it. Anyone using this data set could well be mislead by the timestamps. 80n 13:09, 3 Dec 2005 (GMT)

FAQ - license

Just been looking around the site, wondering what the license for our geodata is. (e.g. is it Creative Commons, or public domain, or something else?) Should that be a FAQ? Ojw 17:04, 4 Dec 2005 (GMT)

The license page is here OpenStreetMap License. It is referenced on the Wiki main page. There is also a direct link to Creative Commons on the main site entrance http://www.openstreetmap.org. I just noticed however that the Copyrights link on the wiki editing page goes to an empty page at the moment (but not for much longer). 80n 17:12, 4 Dec 2005 (GMT)
Thanks, I just spotted the CC logo on the main page after I wrote that. Ojw 17:38, 4 Dec 2005 (GMT)

Maximum length of a way

Here it says the maximum length of a way should be 10-15 km. Can someone add something to explain why this suggestion was made? Is this for performance reasons? Is it possible that it would be better to suggest a maximum number of nodes?

Segments more than 10km long might go missing from tiles@home maps because both the start node and the end node can be outside of the 10km^2 tile area, even if the segment goes directly across that tile. Ojw 08:38, 22 June 2007 (BST)
One other example: if you download a small village and render it. If that area contains part of a 500km road, the entire road will be downloaded and rendered by most current tools. Some renderers will then give you a huge map scaled to fit the very long way, and only using a small part of the image for the area you were trying to render. Ojw 08:38, 22 June 2007 (BST)
I don't feel that 10 km is a useful limit for motorways with a total length of several hundred kilometers. 10 km may be less than the distance between two links. --Traut 17:05, 2 January 2008 (UTC)

Tile rendering

The "I have just made some changes to the map. How do I get to see my changes?" bit is quite obscure for people just starting mapping. Would it be possible to expand on this, in somewhat less terse style? ExTechOp 12:12, 16 August 2007 (BST)

Tax

Actually in the UK and possibly elsewhere, taxes don't pay for the mapping. Ordnance Survey makes more money than it spends and even gives some back to the government. From [1] "The surplus for the year [2006-2007] is £6,223,000. A dividend of £4,610,000 for the financial year is payable to Communities and Local Government." Still I think it would be better if their data was free for personal use, or something like that. Timmmm 15:21, 23 September 2007 (BST)

Ah, but their profits are still ultimately from taxes - very large parts of OS's income are from central and local Government, i.e. raised through taxation. --Richard 18:26, 23 September 2007 (BST)
Yes it "gives money back to the government". It's a trading fund, so it has to turn a profit, but as Richard says, its main "customers" are... the government.
Also it should be noted that before it became a trading fund, while it was being set up as an organisation, and while all the initial surveying work was being carried out (the expensive bit)... who was paying for that? The tax paying public. It's publicly owned information... which we have to pay for.
Reading the guardian "free our data" campaign it seems like the tides are turning, and maybe in the next few years Ordnance Survey will release their data more freely. Then we'll have a big import on our hands! :-)
-- Harry Wood 13:33, 26 March 2008 (UTC)

scale

Which scale do the zoom levels have?

Can I print a map and use a guide to measure distances? Is there a reference to calculate the scale?

Hadhuey 21:15, 3 November 2007 (UTC)

http://almien.co.uk/OSM/Tools/Scale/
Thank you Ojw. Is it the same for Mapnik an Osmarender? I will put them in the wiki as official scale factors. Hadhuey 17:58, 5 November 2007 (UTC)


Due to the projection used the scale varies with latitude. I guess the scales in the link above are correct for lat=0 ie the equator only. For all other latitudes the projection makes places to appear bigger and I believe the values need to be multiplied by a factor of cos(lat) to obtain the real scale at that specific latitude.

Also, I believe the distance indicator on the openstreetmap image (lower left corner) is incorrect except along the equator. It should change when moving across different latitudes but it doesn't. Can someone check and/or fix that?

Yes, what's written above is correct. We discussed about it in the Italian list and I've been told to try to fix it. As for the distance indicator, I don't get it any more in the web pages (rubini, 2009-09-16)

Selective maps?

Is it possible to create a map from this that only shows only certain forms of roadway (e.g. only trains/trams/bikepaths)? Felix the Cassowary 07:54, 6 January 2008 (UTC)

Very much so - see the wondrous http://www.gravitystorm.co.uk/osm/ for an example --Richard 18:52, 6 January 2008 (UTC)
Is it easy to do on my own? (Including time-consuming but with an easy set of instructions.) I haven't met many cassowaries native to England :) I'm after a map the aforementioned types of routes through Melbourne, which is probably incomplete so I'll use it as a basis for what I want to work on here. And also, because I want to have a map of those things for greedy reasons. Felix the Cassowary 10:33, 7 January 2008 (UTC)
What you're after is a "custom rendering". Currently this is only possible through a fair amount of technical fiddling with one of the rendering tools.
Kosmos is probably the easiest to get working, but still requires you to do various steps. 1) get an OSM file (easiest way to do this is to install JOSM). 2) fiddle with Kosmos project configuration 3) Modify the default rendering rules to show what you want.
Your other problem is that the whole of Melbourne might be a prohibitively large dataset to try to load into JOSM/Kosmos. So then I think you have to work out the appropriate Osmxapi calls to fetch just the main highways for example.
All in all it's not that easy to do at the moment, but I'm sure there will be some improvments in these directions in the near future. This new web-based tool is a recent advancement. It gives you fairly customised maps on-the-fly, for different types of points of interest. Showing/hiding different types of highways would be a more tricky problem but in a few months someone will have cracked it I'm sure!
-- Harry Wood 13:19, 26 March 2008 (UTC)
All these issues you mentioned will be addressed in the future releases of Kosmos. Currently I'm working on a major redesign of the Kosmos UI to be more multi-window (similar to JOSM). After I finish this, Kosmos will have support for OSMXAPI, GPX, editing the project visually and much more (maybe even 3D rendering using SRTM data). But it will take some time to do this. --Breki 19:09, 26 March 2008 (UTC)

History

Pressing H for a way in Potlach does permit to view the history for that way .... but how to see the changes for a single node ??? (in this case a place) --PhilippeP 10:25, 20 January 2008 (UTC)

This still needs to be implemented. Richard didn't think it was as important for nodes as for ways. I don't agree with that. I guess it's somewhere on his todo list, but I have no idea with what priority. --Polyglot 12:03, 20 January 2008 (UTC)
Any idea how to get the information outside of Potlatch ?? I think I allready saw that information but cannot find it back ! --PhilippeP 13:58, 20 January 2008 (UTC)

Nokia Sports Tracker

Have found that Nokia's Sports Tracker works reasonably well as a GPS logging system on my Nokia E71. Not particularly accurate, but good enough for marking out where roads are. I hope to test other E71 features, such as voice recorder and camera, in conjunction with this at a later date...

There's a problem with the GPX that Sports Tracker outputs: although it includes

Will have to see what the difference in file format is. Wonder whether it's a problem with OpenStreetMap's importer, or Sports Tracker's output...

If you could post the (non-uploading) GPX somewhere, we'll have a look at it... --Richard 13:19, 24 November 2008 (UTC)
Thanks Richard, it seems that Nokia Sports Tracker's GPX output is technically invalid, as its trackpoint sub-elements currently (a) are in the wrong order and (b) include "speed" and "course" which aren't allowed unless in an "extensions" element. I've sent feedback to Nokia telling them this. I don't know why GPX requires a particular element order for points, but it does. OpenStreetmap's GPX loader would load them if it didn't mind the fact that <time> isn't the second element as the GPX spec requires: both GPX editor and EasyGPX load the file and find the <time> elements, and then write the file back with the elements in the correct order. --Fonant 09:53, 25 November 2008 (UTC)

'Datums'?

The plural of datum is data (at least according to the OED). Often, if the Latin plural is not well-known, you can use a plural in -s instead (for example you often say indexes not indices). But that is not the case here; the Latin plural data is a common word but 'datums' is just odd-sounding and doesn't seem to be in the dictionary.

'datums' is the commonly accepted plural in GIS. OSM has reinvented pretty much everything else about GIS, I think we can cut them some slack on their Latin neuter plurals. --Richard 14:07, 14 December 2008 (UTC)

Where can I ask questions?

I am missing this topic and there does not seem to be a page here in the wiki where someone could ask questions. --Poi 09:52, 15 January 2009 (UTC)

This topic is covered on the FAQ: FAQ#How do you communicate? ...and in more detail on the Contact page.
There isn't a page on the wiki specifically for asking questions. You can ask questions in relation to topics covered by specific pages on the wiki, but in general I would recommend a different contact channel. Mailing list, IRC or the Forum are all better for asking questions. The fact that nobody answered you here in over a year will illustrate why :-)
-- Harry Wood 11:19, 20 May 2010 (UTC)

Page too big. Too many FAQs

The FAQ page is too big. There are too many FAQs. Some of them are clearly not "frequently" asked. And some of the answers are too verbose, and could be covered by linking to pages elsewhere instead. There's wiki warning "page is more than 36 kilobytes long", but also from the point of view of usability of the page, we need to prune it a little. -- Harry Wood 11:06, 16 February 2009 (UTC)

The semicolon trick

Quick questions before I fix the FAQ entry for it: how widespread is support for the semicolon trick for separating multiple "values" within a single string? Is it a general thing that you can do for every tag regardless of how it's defined? Does doubling the semicolon work everywhere (or: should it)? And finally, if it's something you can do everywhere, then why do we have alt_name=* etc.?

I can see it being more useful for values that are ref=* codes, or values from a (semi-controlled, underscore_separated lower_case_words) dictionary defined somewhere within the grand union of wiki, editor presets and current usage. And far less useful for values like those of name=* or note=*. --achadwick 01:52, 26 April 2009 (UTC)

Pub icons

So how do I disable the pub icons in the default map views? In a professional context they're faintly inappropriate ("here are directions to our offices; as you can see, there are many pubs nearby"), and in a simple informational context, it's a layer of data that the end user probably isn't going to need (and if it's just a load of unlabelled pint-glass icons, I'm going to have to explain them before the reader can ignore them). If there are only one or two pubs then I can just photoshop them out, but in somewhere like central London, it's a lot of work to remove them cleanly every time I want to use OSM for something.

Am I missing a simple toggle switch somewhere? --Kevan 11:31, 3 June 2009 (UTC)

It's a simple stylesheet configuration change if you have your own Rendering set-up, but for a "simple toggle switch" the closest thing would probably be CloudMades style editor. -- Harry Wood 11:24, 20 May 2010 (UTC)

Integration of answers from help.openstreetmap.org

There's at least one instance where the same question example was asked on the help website and is also listed in the FAQ. Should the answer in the FAQ be rewritten to include all of the information in the answer[s] and/or add a link to the answer on help site ? Skorasaurus 20:00, 17 December 2011 (UTC)

What shall I do for roads that have multiple values for a tag?

Is this really a frequently asked question? I suspect a few of these questions can be removed in order to simplify the entire page.

-- User:OpenBrian 03:57, 18 May 2014

Not necessarily for roads, but yes it is a frequently asked question for things like POIs. --Jgpacker (talk) 00:24, 26 May 2015 (UTC)