[postgis-users] transformation discrepancy with postgis v. cs2cs

[Bryan Keith]

>>>
>>> Something is definitely strange with the PROJ.4 installation on that
>>> one system. If I had to guess, you compiled PROJ.4 yourself, but
>>> didn't unzip the gridshift files in the nad folder before ./configure
>>> ? It should be apparent that the grid shift files are installed with
>>> the make install command.
>>
>>
>>>
>>> Try reinstalling the PROJ.4 library with the gridshift files intact,
>>> and it should affect both PostGIS and cs2cs (since they use the same
>>> system library).
>>
>> Should I just try:
>>
>> sudo apt-get install proj
>
> I tried this and got the message:
>
> proj is already the newest version.
> proj set to manually installed.
>
> Manually installed?  I wonder why that is.
>
> Where is it installed?  I search for a nad directory and only found this
> one:
>
> /usr/lib/grass/etc/nad
>
> I didn't try doing the coordinate conversion in GRASS since I don't know
> how to use GRASS, but the nad directory seems to have the uncompressed
> grid shift files:
>
> -rw-r--r-- 1 root root 1053896 2008-05-29 14:33 alaska
> -rw-r--r-- 1 root root  264392 2008-05-29 14:33 conus
> -rw-r--r-- 1 root root    8840 2008-05-29 14:33 FL
> -rw-r--r-- 1 root root  451976 2008-05-29 14:33 hawaii
> -rw-r--r-- 1 root root    3528 2008-05-29 14:33 MD
> -rw-r--r-- 1 root root 1113184 2008-05-29 14:33 ntv1_can.dat
> -rw-r--r-- 1 root root  318464 2008-05-29 14:33 nzgd2kgrid0005.gsb
> -rw-r--r-- 1 root root   26696 2008-05-29 14:33 prvi
> -rw-r--r-- 1 root root   59176 2008-05-29 14:33 stgeorge
> -rw-r--r-- 1 root root   26696 2008-05-29 14:33 stlrnc
> -rw-r--r-- 1 root root    7016 2008-05-29 14:33 stpaul
> -rw-r--r-- 1 root root    4392 2008-05-29 14:33 TN
> -rw-r--r-- 1 root root    6728 2008-05-29 14:33 WI
> -rw-r--r-- 1 root root   11080 2008-05-29 14:33 WO
>
> I appreciate any suggestions.  I don't really know what I'm doing here.

I tried reinstalling proj:

sudo apt-get --reinstall install proj

Do I need to do anything else to get the grid shift files?  Where should
they be installed?  In the readme files, they give a cs2cs example, but I
don't get the correct results.  Here's my version:

cs2cs +proj=latlong +datum=NAD27 +to +proj=latlong +datum=NAD83
-117 30
117dW	30dN 0.000

Should be:
117d0'2.901"W   30d0'0.407"N 0.00

Clearly I don't have the grid shift files, but I'm not sure where I'm
supposed to get them or where they're supposed to be.

Bryan