Paul Ramsey escribió:
On Tue, May 20, 2008 at 3:06 PM, Karina Guardado <[EMAIL PROTECTED]> wrote:
1.from the 1.2.0 release of PostGIS there is support for "curve" /types/,
and initial support for the ISO SQL/MM suite of spatial database functions
Yes, and you'll see some sparse documentation on these. There is not
full support of these types by all the functions, in fact very few of
the functions will support them.
2.(from the list)We made a patch to add such new geometries to PostGIS.
It implements TIN and POLYHEDRALSURFACE as described in
OGC SFS1.2 standard.
These geometries are specific MULTIPOLYGON that
describe 3D surfaces and 3D volumes.
Currently, we got the following functions to work for 3D geometries:
- asEwkb
- asEwkt
- asGml
- asSvg (2D output only)
- asX3d.
This last function enables exporting 3D geometries to the X3D format.
I also provide a patch for GEOS to implement the isValid function
for TIN and POLYHEDRALSURFACE. It checks if feature faces
are well connected and well oriented.
So after reading this I feel confused if this geometry types are really
supported or not and I think it is not clear still for me, I would like to
know if there is an official documentation but updated with the last
geometry types supported by Postgis.
This patch exists, as you found it on the list, but it has not been
applied. I have some grave misaprehensions about the whole idea of
modeling large structures like TIN as a single object. However, I am
open to being forced into it by the Will of the People.
Frank is right about LinearRing not being instantiable. I'd have to
check and see but I believe there is no such thing as an instantiable
Curve, just CurveString. At least, a single curve isn't very useful
as an object.
P.
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Thanks a lot for your help I really apreciate it. Just one more question
in the web site of Postgis I found the following:
PostGIS follows the OpenGIS <http://www.opengis.org> "Simple Features
Specification for SQL <http://www.opengis.org/docs/99-049.pdf>" and has
been certified as compliant
<http://www.postgis.org/files/opengis-certification.png> with the "Types
and Functions".
At first reading I thought that Postgis support all of the features
types specified in the OGC geometry model. But now as you explained me
there is not support for all of this then could you please explain me
about this compliant if this mean that you support only some but not
necessary all and then you get the compliant.
In fact I'm doing a research in the university about the simple feature
access and a comparison with the different spatial databases:
postgres(postgis), oracle, mysql , db2 . So I need to be really clear
respect to this because I don't want to publish something that is not
true so I 'm really thanks for your help. When I finish the document I
will sent you a copy.
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