[GRASS5] Some Bugs

[Morten Hulden]

On Wed, 13 Dec 2000, Eric G . Miller wrote:

> If there's some reason for having both upper and lowercase names for
> these, can't we just "alias" the names somehow?

Having duplicate upper and lower case entries in etc/ellipsoids would be
the fast and ugly hack. Going to lower case only is what most people would
prefer, but that would also mean fixing PROJ_INFO entries for existing
locations.

> And to be even more of a pest.  Is there something special about UTM?
> why should it be handled differently than all the other projections?

I think everyone who has tracked the code in g.setproj and associated
modules will agree its an ugly mess. There is nothing special about UTM -
PROJ could handle it as any other projection, but _only_ for historical
reasons it's treated separately. Changing it is not easy though, as it
means changing all 'wrapper' code in all modules that treats UTM and LL
differently.

> Seems we should have:
> XY data (unreferenced)
> Unprojected (lat/lon)
> Projected (projection)
> I know there's a hysterical (I mean historical) reason for this, but it
> would seem logical to do this.

I agree something has to be done, but I would hesitate to start messing
with it before 5.0 is out. A redesign during 5.1 I feel is more
appropriate.

By the way, how far are we from dynamic projections? I could imagine
storing data in geocentric coordinates and only projecting when the user
needs a flat surface image (screen/printer/export) is feasable with the
processing power of computers today. Perhaps first as specially flagged
locations to keep backward compatibility. This could open up new
possibilities such as animated remorphing of maps through different
projections.

regards
Morten Hulden



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