[OSRS-PROJ] NTv2 (.gsb) grid shifting support

[Mike Thomas]

Hi there.

Paul wrote:

| Hello Frank,
| Since Proj4 is a working code being used in many applications,
| I think it will be better to commit only working codes.
|
| Not everyone will read this, and some may even join the list
| later. In fact, you do not have to join the list to use the Proj4 :((
|
| Best regards,
| Paul.

Working users should always stick with stable released versions of code (in
this case the current source release marked as such) on:

  http://www.remotesensing.org/proj/

Possibly a note could be added to emphasize that fact on the web page.

CVS is meant to be used by developers as code goes through possibly major
and difficult changes.  The general understanding on every project I have
ever worked on is that HEAD CVS code is by definition unstable and to be
treated with caution.

Consequently, I think that Frank is entitled to use CVS in this way,
especially as he took the trouble to warn others of potential difficulties.

I know of three open source projects where insufficient use of CVS by
developers has contributed to major problems.  In one case, a hard disk
crash caused the loss of the entire Windows port of the Rosegarden MIDI
sequencer - that project has never been revived.  In the other two projects
(Maxima and Gnu Common Lisp) the unfortunate and unexpected death of the
maintainer (without having committed vital files to CVS) meant that many
people have worked long hours over an entire year to put the projects back
on track.  (Naturally, I hope Frank won't be negotiating the latter event in
his life for some time!)

Cheers

Mike Thomas.


Frank wrote:

| > Folks,
| >
| > I have preliminary support for Canadian NTv2 grid shift files
| incorporated
| > into PROJ.4 with some major flaws still (it does not pick the
| most refined
| > grid).  This is the same .gsb format used by some other organizations,
| > notably in Australia.
| >
| > I write this to warn people that the structural changes in
| PROJ.4 (in the
| > datum shifting area) were substantial and are not really quite complete
| > so take care using PROJ.4 from CVS for a week or so.
| >
| > Best regards,
| >
| > --


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