Yep. For the downgrading I tried it a while ago for a subset of the same schema, https://github.com/Remi-C/pointcloud/blob/master/lib/pc_api.h#L445
The idea was that usually we don't need all dimensions, particularly when working on the geometry. So I wrote a couple of functions to allow a pc_explodes with only a subset of dimensions. The condition was the dimension should have the same name. I guess non mapped dimensions could be filled with O or null or Nan? Cheers, Rémi-C 2014-10-31 1:04 GMT+01:00 Paul Ramsey <pram...@cleverelephant.ca>: > Correct, I was thinking more PC_Transform(pcpatch, pcid), which would look > for common dimension names and map between them by default, or could maybe > accept a mapping (dim->dim) to control the conversion. But yes. Danger I > suppose in downgrading data (pushing a 4 byte into 2 byte) but that could > be left to users to avoid or not on their own (emit warnings on downgrades > maybe). > > On Wed, Oct 29, 2014 at 4:54 AM, Rémi Cura <remi.c...@gmail.com> wrote: > >> I'm sorry I think I was unclear. >> I don't want to acces point, >> I just want to change the pcid of a patch. >> For the moment it seems to imply a complete destruction/reconstruction of >> a new, >> which is really really not efficient. >> >> Basically in this case I would like a function PC_SetPCID(pcpatch) >> I understand that such function is very hard to create in the genral >> case, because you would have to put mappings between attributes. >> >> >> Cheers. >> Rémi-C >> >> >> >> >> 2014-10-28 19:08 GMT+01:00 Stephen V. Mather <s...@clevelandmetroparks.com >> >: >> >> Ah. Yes, I think if you are accessing a point within a patch, you have >>> to unpack the patch. It's one of those tradeoffs... >>> >>> >>> [image: http://sig.cmparks.net/cmp-ms-90x122.png] Stephen V. Mather >>> GIS Manager >>> (216) 635-3243 (Work) >>> clevelandmetroparks.com <http://www.clemetparks.com> >>> >>> >>> >>> >>> ------------------------------ >>> *From:* postgis-users-boun...@lists.osgeo.org < >>> postgis-users-boun...@lists.osgeo.org> on behalf of Rémi Cura < >>> remi.c...@gmail.com> >>> *Sent:* Tuesday, October 28, 2014 1:33 PM >>> *To:* PostGIS Users Discussion >>> *Subject:* Re: [postgis-users] pointcloud : change pcid ? >>> >>> Now the only solution I found is to break a patch into point, then >>> break point into attributes, >>> then construct a new point with correct pcid and attributes, then >>> construct a new patch ! >>> Cheers, >>> Rémi-C >>> >>> 2014-10-28 17:31 GMT+01:00 Stephen V. Mather < >>> s...@clevelandmetroparks.com>: >>> >>>> How do you mean? What are you doing now? >>>> >>>> >>>> [image: http://sig.cmparks.net/cmp-ms-90x122.png] Stephen V. Mather >>>> GIS Manager >>>> (216) 635-3243 (Work) >>>> clevelandmetroparks.com <http://www.clemetparks.com> >>>> >>>> >>>> >>>> >>>> ------------------------------ >>>> *From:* postgis-users-boun...@lists.osgeo.org < >>>> postgis-users-boun...@lists.osgeo.org> on behalf of Rémi Cura < >>>> remi.c...@gmail.com> >>>> *Sent:* Tuesday, October 28, 2014 11:01 AM >>>> *To:* PostGIS Users Discussion >>>> *Subject:* [postgis-users] pointcloud : change pcid ? >>>> >>>> Hey, >>>> any pointcloud users has an idea about changing the pcid of a patch >>>> without breaking it into pieces? >>>> Cheers, >>>> Rémi-C >>>> >>>> _______________________________________________ >>>> postgis-users mailing list >>>> postgis-users@lists.osgeo.org >>>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >>>> >>> >>> >>> _______________________________________________ >>> postgis-users mailing list >>> postgis-users@lists.osgeo.org >>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >>> >> >> >> _______________________________________________ >> postgis-users mailing list >> postgis-users@lists.osgeo.org >> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >> > > > _______________________________________________ > postgis-users mailing list > postgis-users@lists.osgeo.org > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >
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