[GRASS-dev] PROJ 4.6 vs 4.5 and GDAL 1.4.1 vs 1.5.0

[Frank Warmerdam]

marco.pasetti at alice.it wrote:
> Hi,
>  
> mybe these are boring questions for you, but I need to have a clear view 
> before to proceed (the following intended for Win32 under MinGW).
>  
> 1) I tried to build latest PROJ (4.6) but, for ibscure reasons, it 
> doesn't create libraries. There are essential reasons to move to 4.6 or 
> can I quietly use 4.5 instead?

Marco,

The main difference between PROJ 4.5 and 4.6 is that 4.6 does not apply
any shift when going from one ellipsoid to another unless there is
datum shift information available for both the source and destination
coordinate system.  I suspect this will not matter in normal use for
GRASS.

> 2) The same problem for GDAL. I built it using 1.4.1 source code, while 
> the latest release is 1.5.0; now I'm compiling PROJ, so I cannot test 
> it, but I'm sure that it will be an hard thing to do... but well done if 
> for a good reason ;-)

There are a variety of improvements in GDAL 1.5 but none of them are
required by GRASS.

I would note that I am working on changes to GRASS and GDAL so that
WinGRASS can use the standard GDAL builds (prepared with visual studio).
I have successfully prototyped this on my own system.

> *sorry to be so obstinate, but with my old pc it takes very long time to 
> compile (about 3 hours for grass only!), so it's very frustrating to 
> wait so much time and then discover that it went wrong, and, actually, 
> that it was not really an important issue!*

Whew!  I sympathize, but perhaps a newer computer would be cheaper
the the cost to you in frustration!  Or perhaps use canned binaries
for most of your needs.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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