<div dir="ltr">Sean and everyone, I meant to follow up on this earlier, sorry. I see the discussion has moved on to simply removing the CRS, so just wanted to reply to this:<div><br>
</div><div>> Other than Mike's election maps, what would break if we made crs an optional string (defaulting to "urn:ogc:def:crs:OGC::CRS84") instead of a JSON object?</div><div><br></div><div>
Actually nothing discussed here (including removing CRS from the spec entirely) will break my maps, present or future, so no worries there. My Python code gets GeoJSON output from PostGIS and augments it with some extra properties like the CRS, and then my PolyGonzo code in the browser checks the CRS. That will all keep working regardless of whether this is official GeoJSON or my own addition - I don't depend on any other code supporting the CRS property.</div>
<div><br></div><div>So, carry on! :-)</div><div><br></div><div>-Mike</div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, May 1, 2013 at 1:56 PM, Sean Gillies <span dir="ltr"><<a href="mailto:sean.gillies@gmail.com" target="_blank">sean.gillies@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div>Howard, I can't let you take all the blame for GeoJSON's crs. A lot of that is my doing. And I think you're right that projection in the browser (like <a href="http://bl.ocks.org/mbostock/4498292" target="_blank">http://bl.ocks.org/mbostock/4498292</a> or <a href="http://bl.ocks.org/mbostock/4319903" target="_blank">http://bl.ocks.org/mbostock/4319903</a>) changes the game entirely. All projecting geographic servers aren't as necessary as they used to be and long/lat (<span>"urn:ogc:def:crs:OGC::CRS84") is increasingly sufficient.<br>
</span></div><div><br></div>Mike, I'm in favor of a single indentifier string for crs as you have above for cases where long/lat just won't do. And I think that use of RFC 5165 URNs like "urn:ogc:def:crs:EPSG::3857" make the most sense for a GeoJSON I-D. Perhaps a future CRSJSON could address cases not covered by OGC or EPSG.<br>
<br></div>Other than Mike's election maps, what would break if we made crs an optional string (defaulting to <span>"urn:ogc:def:crs:OGC::CRS84")</span> instead of a JSON object?<br></div><div class="gmail_extra">
<div><div>
<br><br><div class="gmail_quote">On Fri, Apr 26, 2013 at 11:42 AM, Michael Geary <span dir="ltr"><<a href="mailto:mg@mg.to" target="_blank">mg@mg.to</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div class="gmail_extra"><div>On Fri, Apr 26, 2013 at 9:27 AM, Howard Butler <span dir="ltr"><<a href="mailto:hobu.inc@gmail.com" target="_blank">hobu.inc@gmail.com</a>></span> wrote:<br><div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">As one of the primary forces behind the CRS stuff, I support the removal of CRS from the GeoJSON specification. Adhoc specification of the coordinate system would then be left to the implementor, and a thousand turdblossoms can bloom.</blockquote>
</div><br></div>I'm one of those rare people who use the GeoJSON CRS. I built a bunch of election results maps for Google over the last few years, and to speed up the JavaScript code a bit I used Spherical Mercator coordinates since those convert directly to pixels with a single multiplication. So I use this CRS in my GeoJSON files:</div>
<div class="gmail_extra"><br></div><div class="gmail_extra"><div class="gmail_extra"> "crs": {</div><div class="gmail_extra"> "type": "name",</div><div class="gmail_extra"> "properties": {</div>
<div class="gmail_extra"> "name": "urn:ogc:def:crs:EPSG::3857"</div><div class="gmail_extra"> }</div><div class="gmail_extra"> }</div><div><br></div></div><div class="gmail_extra">
with coordinates like these:</div><div class="gmail_extra"><br></div><div class="gmail_extra"> "bbox": [ 737758, 4231185, 2061653, 5957068 ]<br></div><div class="gmail_extra"><br></div><div class="gmail_extra">
I suppose it wouldn't make any real difference whether the crs object is in the standard or not, since I could just continue to use it in any case. Maybe if it weren't in the standard I would feel free to simplify it to:</div>
<div class="gmail_extra"><br></div><div class="gmail_extra"><div class="gmail_extra"> "crs": "urn:ogc:def:crs:EPSG::3857"</div><div class="gmail_extra"><br></div><div class="gmail_extra">
instead of all the extra structure it has now.</div><div class="gmail_extra"><br></div><div class="gmail_extra">So I guess I don't have an opinion one way or the other on removing the CRS from the standard, just wanted to mention that I'm using it.</div>
<div class="gmail_extra"><br></div><div class="gmail_extra">-Mike</div><div><br></div></div></div>
</blockquote></div><br><br clear="all"><br></div></div><span><font color="#888888">-- <br>Sean Gillies
</font></span></div>
</blockquote></div><br></div></div>