How to tag a country club?

ponzu · 2011-03-25T00:47:44.000Z

A country club (at least the ones I am looking at in the Palm Springs, CA area) is a private residential community for rich old people built around a golf course.

Is it fair to tag it leisure=golf_course or should there be a distinction between a golf course that’s just a golf course and a golf course that is part of a country club?

Example of tagging a country club as a golf course: http://www.openstreetmap.org/browse/way/105658536

Here’s an example of (someone else) attempting to draw just the outline of a golf course inside a country club and tagging it as such: http://www.openstreetmap.org/browse/way/47825422

To me, it’s misleading. Some of the streets and houses got inside the outline and are now part of a “golf course”. Why not the rest, right?

PHerison · 2011-03-25T10:04:33.000Z

A golf course is a golf course, no matter if it is part of a private property or a public area. Access restrictions can be tagged directly to the golf course or to the area sourrounding the course.
I don’t think we have a special tag for “country club”. The closest thing which comes into my mind is leisure=park;access=private;name=“XYZ Country Club”.

Vclaw · 2011-03-25T14:29:33.000Z

I’m not sure exactly what you mean by ‘country club’, but maybe you could use this proposed tag for leisure=social_club
http://wiki.openstreetmap.org/wiki/Proposed_features/social_club

ponzu · 2011-03-25T16:29:58.000Z

Vclaw:

I’m not sure exactly what you mean by ‘country club’, but maybe you could use this proposed tag for leisure=social_club
http://wiki.openstreetmap.org/wiki/Proposed_features/social_club

A country club is a private residential community for rich old people built around a golf course.

No, it’s not the same as a social club, because people live in a country club. I know, the term is somewhat counterintuitive. It took me a while to figure out what a country club was, too. When you look at a map of the area where my links point, you will see a lot of country clubs and will get an idea of what they are. The question is how to tag them.

ponzu · 2011-03-25T16:59:27.000Z

PHerison:

A golf course is a golf course

I am starting to think you are right. I have talked to golfers, and it sounds like they think of country clubs in terms of the golf courses, not the residents.

I was not worried about private vs. public. I was thinking more in terms of someone who lives in a country club looking at a map and saying: “I live in a golf course, really?” But from talking to my friend it sounds like that would be par for the course There is no point in living in a country club if you don’t plan on playing at least every day.

So yeah, that’s how I will tag them. Thanks!

I guess one point of clarification is: if look at the two links I originally posted, you will see two distinct approaches to drawing the outline of a country club. One (mine) involves drawing the outline of the gated residential community, which encompasses the golf course. The outline is usually regularly shaped on at least a few sides - where the streets are.

The other is drawing an irregularly shaped outline of just the golf course inside the country club.

Which is correct/better?

ponzu · 2011-03-25T23:12:26.000Z

Actually, there is a third option, which I, time permitting, may apply.

Make the outline of the country club an outer member of a multipolygon relation, then cut out as many holes as necessary for the residential streets and blocks of houses. Here’s an example: http://www.openstreetmap.org/browse/relation/1505850

This appears to cover all bases: the country club in its entirety is still marked by an outline so tagged, while the rendered map only shows green where the actual golf course is. I believe Google follows this method: http://maps.google.com/maps?f=q&source=s_q&hl=en&ll=33.715523,-116.317105&spn=0.023988,0.038195&z=15 while Bing believes in shading the whole polygon: http://www.bing.com/maps/?v=2&cp=33.71468436520902~-116.31590387373392&lvl=15&dir=0&sty=r&FORM=LMLTCC

SK53 · 2011-03-26T11:33:21.000Z

If the golf course & residential area are all part of the same organisation (for instance, owning property confers special access rights to the golf course) I think it makes sense to a) tag the whole area with a residential polygon perhaps with the name of the organisation; and b) add the golf course as a separate polygon. I suspect that mapnik renders golf course on top of residential areas, so this would appear with a shaded residential area overlain with the golf course.

The alternative is as you suggest : adding an operator tag to both residential area and golf club would help show that these are indeed linked.

This issue has been discussed on the wiki Golf page here: http://wiki.openstreetmap.org/wiki/Talk:Proposed_features/Golf_course#Golf_.22communities.22. The recommendation was to interleave the residential & golf course areas.

Your last method is quite ingenious, but may rely on artefacts of how mapnik renders multipolygons: it may break when such data are pulled into a conventional GIS tool.

BTW: I tidied up the roads in your original example.

ponzu · 2011-03-30T20:19:38.000Z

Thank you for your thoughts and for tidying up an area within my example.

Firstly, I wanted to clarify that yes, we are talking about the situation when the golf course and residential area are all part of the same organization, and owning property does confer access rights to the golf course, much like not owning property precludes such access (unless one is a guest of a member). We can call these golf communities if the term “country club” is too geographically specific and, perhaps, a bit too broad as I imagine there exist country clubs in the US or elsewhere that do not include a golf course.

So, speaking of golf communities - I would be extremely reluctant to create two overlapping polygons for the residential community and the golf course. Primarily, that would defeat the purpose of defining an object as “golf community”. It would define a “residential community” and a “golf course”, not a “golf course with a residential community built into it” (or vice versa). Secondly, it could lead to rendering issues if we were to tag the name on both the residential polygon and the golf_course polygon. Not to mention it’s too much work ant twice the number of nodes not that anyone is counting.

Note that in the example from the wiki discussion you linked, the “good (and early) example” of tagging such community in England does not use an additional polygon for the residential, it simply calls the whole thing a golf_course. Granted, they have considerably fewer houses on the golf course than in my examples from Southern California.

I wanted to be clear on what you meant by

The alternative is as you suggest : adding an operator tag to both residential area and golf club would help show that these are indeed linked.

What’s an operator tag and which one did I suggest adding? I am relatively new to OSM and some of the lingo tends to stump me.

Having considered your suggestion, my own experience, the brief discussion on wiki and other people’s attempts, I would say this:

DO

Draw a polygon around the entire golf community and tag it landuse=residential; leisure=golf_course; access=private; name=XYZ Country Club.
(Optionally and time permitting) Create a multipolygon relation and cut out as many “inner” holes as there are distinct and sizable pockets on the aerial image showing homes and roads as opposed to fairways, roughs, hazards, greens and such.

DO NOT

Draw an outline of as much of the golf course as you can with one polygon, tagging it leisure=golf_course. What about the rest of the golf community you are leaving outside the polygon?
Draw multiple polygons where you see the parts of the golf course on the aerial image tagging them all as leisure=golf_course; name=XYZ Country Club Golf Course. Rendering looks terrible with the name of the club repeated over and over on each green area.

Also, when you refer to my last method (using multipolygons and adding holes for the non-golfing pockets in a golf community) you talk about me being at the mercy of Mapnik. Are you suggesting that all multipolygons may break when pulled into a conventional GIS tool? I tend to treat multipolygons as an established and useful OSM tool. Any renderer, official or not, that does not respect them, would be severely crippled. But even so, following my DOs would result in the best possible representation even by a compromised renderer.

The only really crucial rendering assumption I am making is that a golf_course tag trumps the residential tag in shading.

ponzu · 2011-03-30T20:35:05.000Z

Incidentally, here’s an example of something I tried:

http://www.openstreetmap.org/?minlon=-116.3310745&minlat=33.7056745&maxlon=-116.3028735&maxlat=33.7212969

This country club is mapped in accordance with my two DOs, but I went a step further. I tagged the five “inner” pockets as landuse=residential to give them the shading. I don’t know what I think of the result, therefore I did not add it to my DOs.

And here’s a rendering of a TIGER09 import that resulted in a series of polygons (some of them even being multipolygons, wow!) representing a golf course. Each polygon is tagged with the name of course. Not pretty!

http://www.openstreetmap.org/?lat=33.6857&lon=-116.29956&zoom=16&layers=M

I have to say that I am impressed that 1)TIGER has golf courses and 2)the people who worked on the import were able to bring them in as well as they did. But I think these imported courses need a lot of work. Thank goodness for the reviewed=no tag.

SK53 · 2011-03-31T09:56:02.000Z

ponzu:

the “good (and early) example” of tagging such community in England

Ah! good and early referred to the existence of a golf community, not the quality of mapping

Now to the other issues:

Operator tag: This is just used to tag the organisation operating a facility, whether it be a bit of real estate, part of a university, a nature reserve. Operator is used because sometimes the owner might be different. Generally I only use it in specific situations (nature reserves being the main example, name=XYZ Nature Reserve operator=Royal Society for the Protection of Birds). Operator is not rendered but is useful for conveying a lot of information. Historically in Britain land owned by the National Trust has been shown on maps created by the Ordnance Survey

Polygons with holes which meet the outer edge of the polygon do not always behave well. There is a tool called OSM Inspector which has a layer which is designed to root out such rogue polygons. This is quite a sophisticated tool and may be too complex for your needs right now: http://tools.geofabrik.de/osmi/?view=multipolygon&lon=-116.31855&lat=33.71517&zoom=14&opacity=1.00&overlays=invalid_geometry_hull,duplicate_ways,intersections,intersection_lines,touching_inner_rings_hull,touching_inner_rings,role_mismatch_hull,role_mismatch. I’ve written about this type of issue on my blog: http://sk53-osm.blogspot.com/2011/02/exploration-of-bad-polygons.html.

The Indian Wells example looks just fine.

In general we say ‘Don’t tag for the renderer’, this is a) the renderer is only one view of the data, BUT b) because the renderer is not necessarily doing everything its creators want. I’m pretty sure that the golf course split by a road which ideally should be kept as one entity is one such example. (To answer questions like: How many golf courses in Palm Springs? Which is the biggest golf course in Palm Springs?

I do like how you worry away at these problems: its actually the best way to solve them.

ponzu · 2011-03-31T17:14:33.000Z

Got ya! Operator tag as in “operator=*”. I was reading it completely differently, as in mathematical or logical operator.

“Don’t tag for the renderer”. Yeah, I hear that a lot. I suppose you may also say “don’t tag for the routing engine”, etc. All of those are users of OSM data. But it’s sometimes hard to stick to such doctrine simply because one tends to treat Mapnic and skobbler (to pick two examples not completely at random) as black boxes that do what they do and expect what they expect. The only variable I seem to have control over is the OSM data. By varying the data, I may be able to improve how Mapnik rendering looks or how well skobbler directions work, so this is the variable I tend to concentrate on. Anyway, I know it’s “wrong”, I’m just trying to define the cognitive dissonance of sorts.

Also, when I cite what a specific rendering may look like, I do tend to keep in perspective whether that behavior can be improved. When I think of two overlapping (or interleaved – is that the same thing?) polygons with the same name, I can’t imagine how any renderer would NOT show both names in very close proximity on the map, unless one was explicitly tagged renderName=no, but that’s only Osmarender, and besides, what is that if not tagging for the renderer

I did not know about polygons with holes that meet the outer edge being bad. I may have created some in Indian Wells, I will have to check. I will also explore the tool you linked. I use OSM Inspector, but I have never seen the Multipolygon layer in it before. Your link must make it available? And I do see that my multipolygon in Indian Wells is bad in this layer, so will fix.

Also thanks for the blog link. A wealth of knowledge.

P.S. What did you think about my idea to tag the outer polygon of a country club as golf_course and inner holes as residential? Too cute?

ponzu · 2011-03-31T17:38:53.000Z

Looking at OSMI’s Moltipolyogon view of my object: http://tools.geofabrik.de/osmi/?view=multipolygon&lon=-116.31855&lat=33.71517&zoom=14&opacity=1.00&overlays=invalid_geometry_hull,duplicate_ways,intersections,intersection_lines,touching_inner_rings_hull,touching_inner_rings,role_mismatch_hull,role_mismatch

What exactly is the meaning of the Multipolyogn hull? I read up on what a polygon convex hull is. The one drawn in OSMI is not a physical outline in OSM. Is it something OSMI draws on the fly around my polygon for easy visualization? Or is it more meaningful that that?

I realize that OSMI, like you, does not like multipolygons with holes touching the outer edge. Your blog article, while informative (and only slightly over my head), did not explain why this exact problem is a problem. Needless to say, this restriction blows my idea of mapping golf communities as golf_course outer polygons + holes for houses out of the water, as it is quite typical for pockets of houses to be near the edges. I am left with equally unattractive options of drawing the outermost holes as being inside the outer polygon even if by a few pixels, or going the route you initially suggested, having foreseen this complication. Not sure about tagging the name in that case. But the green on gray shading will look nice

I briefly considered the following: 1)Tag the perimeter of the golf community as residential, no name tag, 2)Draw the outline of the golf course as a proper multipolygon, still no name tag, 3)Add both to a relation and tag the relation with name=XYZ Country Club.

The rendering will be fine, but the data may be compromised as we will have a no-name residential development and a no-name golf course - until someone looks at the relation they are part of, and that’s not a given.

ponzu · 2011-03-31T22:43:09.000Z

Depending on when you read the last post and click the link, it may not show the same errors I saw - because I fixed them, in a way. I think I may have gone above and beyond the call of duty in trying to follow you original advice to interleave, and created two rather elaborate polygons, which partly overlap and partly complement each other. The rendering looks sweet, and I took care of the repeating “Indian Wells Country Club” name by replacing the “name” tag with the “operator” tag on the residential polygon. Can’t wait to see what OSMI thinks of my effort when it refreshes.

If I understand your advice correctly, this is what you would have me do, maybe not with such elaborate border tracing, but that’s the approach, no?

I wish it was doable with a single golf multipolygon with residential holes, but those holes would necessarily touch the borders and without fully understanding why that’s bad, I’m taking your and OSMI’s word for it. I still think it would be a more elegant solution, but I realize that I am only looking at it from a rather narrow perspective.

ponzu · 2011-04-01T00:04:42.000Z

Trying to get some kind of closure here, I will list a few permalinks and resist the temptation to make anymore edits so that my examples are still valid overnight.

In my opinion, the adjacent Eldorado and Vintage clubs shown here http://www.openstreetmap.org/?lat=33.70654&lon=-116.35241&zoom=15&layers=M look every bit as nice and are tagged as fully as the Indian Wells Country Club shown here: http://www.openstreetmap.org/?lat=33.71304&lon=-116.31469&zoom=15&layers=M The former are drawn following just my first DO. The latter follows the first and second DOs plus the additional advice to interleave a polygon for the residential parts. That represents about 20 minutes’ worth of extra more work. Is it worth it?

Compare these to the three clubs and five courses shown here: http://www.openstreetmap.org/?lat=33.71304&lon=-116.31469&zoom=15&layers=M From left to right:

La Quinta Resort and Club Mountain Course: a combination of two separate simple polygons, each tagged with name. At zoom level 15, the name is shown once, but it is in “no man’s land”. At zoom level 17, both names are shown, one on green, one on blank land.
La Quinta Resort and Club Dunes Course: same configuration, same issue.
La Quinta Resort and Club Citrus Course: a combination of four separate simple polygons, of which three, incredibly, are attached. Same rendering issue where at zoom level 16 all four names are rendered. Moreover, the map user has no idea of the shape or size of the La Quinta Resort and Club, which encompasses these three courses. The only possible good of this approach is visual delineation between the three courses, which otherwise would be lost inside a massive green blob called La Quinta Resort & Club. The question is how to preserve this useful feature, while combating the shortcomings.
La Quinta Country Club (you would think they could come up with less confusing names) is comprised of a multipolygon and two simple polygons, each tagged with name. Already at zoom level 15 two of the names are showing, at level 16 all three are. Again, way too much blank land in between green blobs, leaving room for imagination as to which of three adjacent clubs it belongs to.
Rancho La Quinta Country Club: a more convincing tracing job with an impressive multipolygon that covers most of the property and holds well together if not for a hard to explain extra polygon on the NE corner, whose name comes through at zoom level 16, and a tagging mistake on one of the inner holes which causes the name to be rendered along the way (easily fixed).

In comparing all these examples, I don’t want to go too far too quickly in the direction of a pretty map. Tagging and tracing have to be useful for a variety of purposes. (I like your sample questions: How many golf courses in Palm Springs? Which is the biggest golf course in Palm Springs?) I guess I want to have it all: show the interconnectedness of the golf course and the residential community AND nail the size and shape of the golf course proper. I’d hate to find out that the answer points back to what I though was an overdone effort on the Indian Wells Country Club.