[Proj] NAD problems on OSX 10.5 Leopard
woklist at kyngchaos.com
Tue Jan 15 21:00:28 EST 2008
This is an odd one. On OSX 10.5 (Leopard), as a 64bit binary PROJ/
cs2cs correctly translates betwen NAD27 and NAD83. But, as a 32bit
binary it translates in the opposite direction. The OSX 10.4 (Tiger)
build (32bits-only) also correctly translates datums (ie, it's the
same as the 64bit translation).
$ cs2cs +proj=latlong +datum=NAD27 +to +proj=latlong +datum=NAD83
118d0'3.385"W 37d59'59.751"N 0.000
$ arch -i386 cs2cs +proj=latlong +datum=NAD27 +to +proj=latlong
117d59'59.748"W 38d0'3.385"N 0.000
The Tiger binary, even running on Leopard gets the translation
correct, so I wonder if something is happening in the compilation.
long's can be trouble, since on 32bit OSX they are 32bit, but on 64bit
OSX they are 64bit. Looking at nad2bin (and a few library sources), I
see that longs are used in the NAD tables (lam and phi), so the NAD
binary files are getting built with 64bit longs, then the 32bit PROJ
is trying to read 32bit longs.
Are the NAD tables meant to always be 64bit longs? Should long long
be used instead, to guarantee 64bit longs, or maybe they should be
William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>
All generalizations are dangerous, even this one.
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