[OSM-dev] 0.6 - older trackpoints /was: Re: 0.6

Stefan Baebler stefan.baebler at gmail.com
Wed May 7 07:47:29 BST 2008


On Tue, May 6, 2008 at 10:25 AM, SteveC <steve at asklater.com> wrote:
>  is there anything else that should be put in 0.6? Probably a good idea
>  to talk about it now.

As project is getting older there are many relatively old GPS tracks in the db.
Older tracks are probably already mapped, or out of date (road network
does change over longer periods), or less accurate (GPS receivers are
improving over time, reducing the errors).
Motorways near bigger cities are sometimes recorded way too often as
mapper's ways converge on their way to/from home.

Having all the ancient trackpoints downloaded into editor can make it
difficult to work with because of the sheer quantity and because it is
can be hard to map recent changes in the road network.

I propose to introduce the ability to limit the age of trackpoints
downloaded into the client by introducing an extra parameter "age",
eg:

GET /api/0.6/trackpoints?bbox=left,bottom,right,top&age=ageInDays&page=pageNumber

To keep it simple age parameter would be in days (can have decimals
for finer precision)
To give tracks such time to be mapped age would be calculated from the
date of trace upload, not the age of individual trackpoint (unless
there is a technical or performance reason to do the opposite).

Editors could choose to use it or not. If they do implement such
filtering there should be an easy way to show all, also older
trackpoints (eg a checkbox in the download dialog).
API might introduce some reasonable default (eg 2 years or longer).

A simpler workaround (with no API change) would be to sort the
trackpoints in the existing api from most recent to oldest and clients
can request as many pages as needed, allowing editors to easily ask
for more (older) trackpoints as needed by requesting additional pages
(and limit first batch to eg 20 pages).

any thoughts?

Stefan




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