[postgis-users] Question on transform.

[Luis Mota]

Hi Frank.

Frank Warmerdam wrote:

> In short, I don't think you can operate on coordinate systems with
> non-greenwich prime meridians properly at this time.
>
> The following bugzilla enhancement request addresses this issue:
>
>   http://bugzilla.remotesensing.org/show_bug.cgi?id=186

 From what I see on this link, you are the person this enhancement has 
been assigned to. Also, I suspect that this enhancement is not a 
priority to you...

The thing is that it is quite important to me, since almost all my data 
is expressed on one of this non-greenwich-prime-meridian-datum. It seems 
to me that this enhancement is not too complicated: it would be a 
question of subtracting the pm value to an input datum and adding it to 
the output, isn't it? Or is it more difficult?

If this is the case, what about if I tried to solve this question? You 
would send me the code and I'd try to contribute with this 
improvement... Is the code written in C? Would you guide me through the 
process and check that the results are correct?

Tell me what you think about this.

>
> There is no schedule for which prime meridian support will be 
> implemented.
> Once that is done appropriate updates to the PostGIS spatial_ref_sys.sql
> will be required. 

This is the easiest part: I have made a simple srtext parser and I can 
extract the pm value.

Bye, Luís