The page "The Open Database of Buildings" has been moved to the "Canada - The 
Open Database of Buildings" not to confuse wiki users from outside the country 
(a Tim Elrick suggestion).

Tim also identified another way to identify local mappers. I added a link to 
his recipe in the above wiki page, in "Get local buy-in before importing" 
section.

Daniel

-----Original Message-----
From: Tim Elrick [mailto:o...@elrick.de] 
Sent: Wednesday, January 15, 2020 17:19
To: Daniel @jfd553; john whelan
Cc: talk-ca@openstreetmap.org
Subject: Re: [Talk-ca] Importing buildings in Canada

Hi all,

I understand your concerns, John. However, many mappers might not follow 
talk-ca. So, I guess, Daniel's suggestion to contact them, might work 
better than waiting for them to incidentally check talk-ca.

* More to finding local mappers *
By providing the overpass query I just wanted to share a different way 
of contacting active mappers in your area. The advantage of Pascal's 
Who's around me is that you can see the mappers with lots of changesets, 
ie. presumably experienced mappers. The disadvantage is that these 
changesets do not have to be from the area we are interested in 
(however, with activity center in the last 6 months we at least make 
sure they were working in our area); another disadvantage is that you 
cannot collect the names of the mappers easily (or am I missing 
something here?). The advantage of the overpass query is that you get 
that list of names easily and you can see how many objects they have 
added in your area in the past months. The disadvantage, of course, is 
that we don't know how experienced the mappers are (but maybe this 
doesn't matter).

Anyway, either approach works as Daniel already pointed out. Thanks to 
stevea, I now know that I can share Overpass queries easily:
for a geocoded area:
http://overpass-turbo.eu/s/PM9
for a bounding box:
http://overpass-turbo.eu/s/PMb

* Contacting local mappers *
I suggest we design a template letter on the wiki page that can be send 
out to local mappers that include the everything that Daniel suggested 
in his last message below.

Tim


On 2020-01-15 15:54, Daniel @jfd553 wrote:
Hi John, Tim, and the others :-)
John, I understand your concern and if it was not addressed properly, 
this could block the import again.

IMHO, we just need to make sure that we have done everything reasonable 
to inform the concerned contributors, in order to discuss the import in 
case they do not agree with it. That is why I proposed the following, in 
a previous email, concerning local mappers buy-in…

1- We contact them to explain our intentions by referring to the 
appropriate wiki pages.
2- We wait a week or two for them to respond to nothing, have concerns 
or want to help.
3- Without negative answers, we could proceed to the import.

The point 3 above make sure the project is not stalled in case there is 
no or only a few answers. The identification of local contributors using 
Neis’ tool, or the query Tim Elrick just proposed, are what I consider 
reasonable attempts for contacting the local mappers.

Daniel

-----Original Message-----
From: Tim Elrick via Talk-ca [mailto:talk-ca@openstreetmap.org]
Sent: Wednesday, January 15, 2020 15:12
To: talk-ca@openstreetmap.org
Subject: Re: [Talk-ca] Importing buildings in Canada

Hi all,

*a) data hosting*
I can offer to host pre-processed data for the building imports as well.

*b) task manager work units*
I find smaller tasks about 20 minutes each more appealing than 1 hour tasks

*c) checking already existing data*
An added tag would certainly help as you can apply a filter in JOSM then.

*d) finding local mappers*
You can use the following query on http://overpass-turbo.eu/ to get a
list of all users in the time period specified in the area specified.

// overpass query
[out:csv(::user)];
// replace Montreal by any known location in OSM, or see code below
// for bounding box use
{{geocodeArea:Montreal}}->.searchArea;
(
     // I collected users active in the last 6 months, but you can
     // change that
     node(newer:"{{date:6 months}}")(area.searchArea);
     way(newer:"{{date:6 months}}")(area.searchArea);
     relation(newer:"{{date:6 months}}")(area.searchArea);
);
out meta;
// end overpass query

Copy the query into the left side of the window and click Export, then
'raw data directly from Overpass API'. This will generate a csv. You can
then count the number of times a name appears in your list by using
LibreOffice, R, Python or Excel. This will give you the number of
objects a user entered in the last 6 months.

If I do this for Montreal I end up with 106 names who have contributed
20 objects or more in the last half year or 46 names who have
contributed 100 objects and more.

You can then use https://www.openstreetmap.org/message/new/USERNAME by
replacing USERNAME with the names from the list to contact these users.

For areas where there is no geocodeArea in OSM you can use the
boundingbox query below. First, zoom to the area of interest (i.e. your
bounding box), then paste the following code on the left and export:

// overpass query
[out:csv(::user)];
(
     node(newer:"{{date:6 months}}")({{bbox}});
     way(newer:"{{date:6 months}}")({{bbox}});
     relation(newer:"{{date:6 months}}")({{bbox}});
);
out meta;
// end overpass query

Tim

On 2020-01-15 12:55, Daniel @jfd553 wrote:
Thanks for the quick replies!

Now, about...

*a) Data hosting:*

Thank you James, I really appreciate your offer (and that of others). So
yes, I think hosting pre-processed data in the task manager, for
approved regions, is an attractive offer. When we agree on a
municipality for pre-processing, I will contact you to make the data
available.

BTW, I thought ODB data in OSM format was hosted with the OSMCanada task
manager. I understand that ODB data are currently converted on the fly
when requested?

*b) Task manager work units for import:*

I agree with Nate, ~ 200 buildings or ~ 1,500 nodes would be suitable. I
was thinking at the same importation rate, but for an hour of work. It
seems best to target 20-minute tasks.

*c) Task manager work units for checking already imported data*

According to Nate, it is definitely not faster than actively importing.
We should then keep the above setup (b).

However, what if I add a new tag to pre-processed data indicating if a
building was altered or not by the orthogonalization (and
simplification) process? For instance, /building:altered=no/, would
identify buildings that were not changed by the process and that could
be left unchanged in OSM (i.e. not imported); /building:altered=yes/ for
those who were changed by the process and that should be imported again.
The same pre-processed datasets could then be made available for all
cases. Thoughts?

*d) Finding local mappers:*

I agree with Nate’s suggestion to try contacting the top 10 mappers in
an area. Using the "main activity center" would work for most of the
contributors but selecting other overlays (.e.g. an activity center over
last 6 months) could also work great. As long as we identify who might
be interested in knowing there is an import coming.

Comments are welcome, particularly about the proposal on c)

Daniel


_______________________________________________
Talk-ca mailing list
Talk-ca@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk-ca



_______________________________________________
Talk-ca mailing list
Talk-ca@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk-ca

_______________________________________________
Talk-ca mailing list
Talk-ca@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk-ca

Reply via email to