[Proj] Re: What proj library version is best?

Thierry Laronde tlaronde at polynum.com
Tue Jul 6 06:53:36 EDT 2004


Hello Gerald,

On Mon, Jul 05, 2004 at 08:00:11PM -0400, Gerald Evenden wrote:
> This discussion reminds me of the email interaction Frank Warmerdam and 
> I
> had about what should be included in a projection library.  My position 
> was,
> and still is, that *only* the projection (conversion between geographic 
> and
> cartesian space) is the domain of the library.  All non-projection 
> elements like
> datum shifts and  x-y-z transformations are separate and unrelated 
> problems
> and belong in their own library systems.
> 
> The reason for this is twofold: 1) projections have uses that do not 
> involve
> datums and their is no reason to burden these uses with elements that 
> are
> not involved and 2) developers often only have expertise in only one of 
> the
> areas and should not have to burden themselves with library maintenance
> involving unfamiliar elements.

I do agree with your points. More generally ---and that is the goal of
the KerGIS project [restarted from last CERL sources of GRASS]--- I'm
fanatic about size of the code (no duplication), orthogonality and Unix
spirit: small programs doing one thing but well.

So your libproj4 will be shipped with KerGIS (due credit, licence notes
being specified on the web site and in the sources as for every portion
of code) and no modifications will be done to libproj4 to "customize" it.
The datum handling, as suggested by Paul and you, will be handled
supplementary to this.
libproj4 will be shipped with KerGIS just in order for people retrieving
it to have a standalone GIS (no need to access external ressources not
included in the tarball). But since it will be used as is, it should not
be difficult for us to keep in sync.

I will send you a message once the library is "officially" included in
the KerGIS sources (should be done in october 2004, perhaps sooner since
this does not represent at the moment huge modifications of the
surrounding KerGIS code).

Best regards,
-- 
Thierry Laronde (Alceste)  <tlaronde at polynum.com>
http://www.kergis.org/  |  http://www.kergis.com/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89  250D 52B1 AE95 6006 F40C



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