[postgis-devel] [PostGIS] #1286: ST_MakeLine and ST_MakePolygon that makes a circularstring, curvepolygon

[PostGIS]

#1286: ST_MakeLine and ST_MakePolygon that makes a circularstring, curvepolygon
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 Reporter:  robe         |       Owner:  pramsey       
     Type:  enhancement  |      Status:  new           
 Priority:  medium       |   Milestone:  PostGIS Future
Component:  postgis      |     Version:  trunk         
 Keywords:               |  
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Description changed by robe:

Old description:

> This stack exchange post got me thinking.
>

> {{{
> http://gis.stackexchange.com/questions/16712/st-makeline-equivalent-for-
> circularstring-in-postgis
> }}}
>
> We have similar issues I think with ST_Collect as far as
> POLYHEDRALSURFACES are concerned.
>
> Lets say you have a set of points that define the points of a
> CIRCULARSTRING, there is no aggregation routine we have that allows you
> to say these points are curve control points, not linear points.
>
> e.g.  I have p1,p2,p3,p4,p5 .. pn points and I want to aggregate to form
> a circularlinestring composed of CIRCULARLINESTRING(p1,...pn)
>
> I propose we overload ST_MakeLine to take an optional argument that
> allows you to pass in CIRCULARLINESTRING, but that defaults to
> LINESTRING.
>
> Same issue with ST_MakePolygon -- we just assume someone wants to make a
> POLYGON from the points not a CURVEPOLYGON.
>

> Same issue with ST_Collect -- When you collect polygons you might be
> collecting to form a MULTIPOLYGON or POLYHEDRALSURFACE
>
> since an ST_Dump(polyhedralsurface) generates polygons

New description:

 This stack exchange post got me thinking.

 http://gis.stackexchange.com/questions/16712/st-makeline-equivalent-for-
 circularstring-in-postgis

 We have similar issues I think with ST_Collect as far as
 POLYHEDRALSURFACES are concerned.

 Lets say you have a set of points that define the points of a
 CIRCULARSTRING, there is no aggregation routine we have that allows you to
 say these points are curve control points, not linear points.

 e.g.  I have p1,p2,p3,p4,p5 .. pn points and I want to aggregate to form a
 circularlinestring composed of CIRCULARLINESTRING(p1,...pn)

 I propose we overload ST_MakeLine to take an optional argument that allows
 you to pass in CIRCULARLINESTRING, but that defaults to LINESTRING.

 Same issue with ST_MakePolygon -- we just assume someone wants to make a
 POLYGON from the points not a CURVEPOLYGON.


 Same issue with ST_Collect -- When you collect polygons you might be
 collecting to form a MULTIPOLYGON or POLYHEDRALSURFACE

 since an ST_Dump(polyhedralsurface) generates polygons

--

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1286#comment:1>
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