VOCAB: schema.org/box has the description for "polygon" #8

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dbs opened this Issue Apr 24, 2014 · 12 comments

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@dbs
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dbs commented Apr 24, 2014

This appears to have been a problem since at least the 1.0b release (the earliest to which I have access).

@danbri danbri added this to the Schema.org v1.3 milestone May 2, 2014
@danbri danbri changed the title from schema.org/box has the description for "polygon" to VOCAB: schema.org/box has the description for "polygon" Jun 15, 2014
@danbri
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danbri commented Jun 15, 2014

Archive.org confirms this has been in error since the start - https://web.archive.org/web/20110925164957/http://schema.org/GeoShape

Nearby but different issue: http://www.w3.org/2011/webschema/track/issues/19
http://geowanking.org/pipermail/geowanking_geowanking.org/2012-June/026179.html

Perhaps something inspired by "A bounding box defines a rectangular region. It is often used to define the extents of a map or define a rough area of interest. " http://www.georss.org/gml.html#gmlbox

e.g. "A bounding box defining a rectangular GeoShape. Can be used to define the extent of a map or an area of interest."

@ManoMarks

To specify it, we may want to do something Well Known Text-ish. While there's no box spec in WKT, we could do something like 'RECTANGLE(x1,y1 x2,y2)'. Similarly we could have WKT specs for polygon and line 'POLYGON(x1,y1 x2,y2 x3,y3 x4,y4, x5,y5 x1,y1)' and 'LINESTRING(x1,y1 x2,y2 x3,y3 x4,y4, x5,y5)' Circle gets trickier since there's no Circle primitive, but we could do something like 'CIRCLE(x,y m)' with m as meters. We could also drop the primitive names, since we already know the type and just give values.

@akuckartz

See #113

@danbri
Contributor
danbri commented Sep 11, 2014

Mano - thanks. I think the ordering should follow WKT unless there's another compelling model already in widespread use. I'm less keen on using pseudo-WKT syntax as it'll risk leaking out and annoying "real" WKT people. So whitespace-separated comma-separated pairs of pairs seems about right.

@ManoMarks

Dan, the only issue with that is that there are no circle or box primitives in WKT, which could be an issue.

@danbri
Contributor
danbri commented Nov 20, 2014

Aside: W3C is beginning work in this area. http://www.w3.org/2014/spatial/charter

We didn't fix this for sdo-venkman, pushing to next release. Will also liaise with W3C.

@akuckartz akuckartz referenced this issue in project-open-data/project-open-data.github.io Jan 28, 2015
Open

Clarify formatting for a bounding coordinate box #423

@danbri danbri self-assigned this Jan 29, 2015
@danbri danbri referenced this issue Apr 16, 2015
Closed

Meta bug for sdo-gozer release - vocab issues #418

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@danbri
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danbri commented Apr 24, 2015

For this looming release, I would like to make at least partial progress here:

  • currently: schema.org/box "A polygon is the area enclosed by a point-to-point path for which the starting and ending points are the same. A polygon is expressed as a series of four or more space delimited points where the first and final points are identical."
  • proposed: "A bounding box defining a rectangular GeoShape. Can be used to define the extent of a map or an area of interest."

Ideal of course would be to have the final sentence giving implementable detail. Can we get that too? (@ManoMarks et al?)

By analogy with polygon, but noting that 2 would be enough, ... "A box is expressed as a series of {x} space delimited points where {y}.".

Any thoughts on x and y? e.g. "2 points", "the points define diagonally opposite corners of a square bounding box."

Any suggestions for x and y?

@danbri
Contributor
danbri commented Apr 29, 2015

Is this enough to be an improvement?: "A bounding box defining a rectangular GeoShape. Can be used to define the extent of a map or an area of interest. A box is expressed as a series of 2 space delimited points corresponding to opposite corners of the box."

@ManoMarks

The most common approach is [minX,minY,maxX,MaxY) where X is longitude, Y is latitude (depending on coordinate reference system). You can see this typified here:
GeoJSON
KML
OSM

@danbri
Contributor
danbri commented Apr 30, 2015

Thanks @ManoMarks, I'll try to merge that in. I believe the heritage of what we have here was (possibly GeoRSS-inspired) via IPTC rNews 1.0 (http://www.iptc.org/std/rNews/1.0/specification/rNews_1.0-diagram.pdf) which was added into schema.org very early. http://dev.iptc.org/rNews-1-The-GeoCoordinates-Class ...

Sorry I should have looked there before! For box they do have "A box is the area enclosed by the rectangle formed by two points. The first point is the lower corner, the second point is the upper corner. A box is expressed as two points separated by a space character.". And the other properties do closely match schema.org. Maybe I should ask them about the heritage and use so far of this?

@danbri danbri added a commit that closed this issue Apr 30, 2015
@danbri danbri Repaired 'box' property definition, which was a copy-paste from 'poly…
…gon'.

It is now restored to the original IPTC rNews text, from
http://dev.iptc.org/rNews-1-The-GeoCoordinates-Class
Fixes #8
The GeoShape text is also adapted to indicate that commas are optional
in lat/long, following the GeoRSS convention from http://www.georss.org/simple
which inspired the rNews GeoRSS design.
e8d937d
@danbri danbri closed this in e8d937d Apr 30, 2015
@danbri
Contributor
danbri commented Apr 30, 2015

Ok I've marked this one closed for now, although I'm sure other specific Geo topics will re-emerge. It seems that schema.org via rNews is closer to GeoRSS than to GeoJSON.

I also took liberty of adding a little more explanatory text to http://sdo-gozer.appspot.com/GeoShape including some words (inspired by the georss site) retrospectively documenting our ambiguity w.r.t. whether point pairs are comma or whitespace based, i.e. we say we don't care.

@RLRichardson

Also check out what3words.com where the entire globe has been mapped into 3X3 meter squares and assigned a name consisting of 3 randomly assigned words

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