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<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>It is most likely the version of proj4. I know when I
went from proj 4.5 to 4.6, (or was it 4.6 to 4.7). 2163 got shifted.
Frank explained is because it was missing information and in prior proj I think
it guessed and in newer it was decided not to make up stuff.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>That was a couple years ago. but it is the same national
atlas projection I am fond of.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>Do a </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>SELECT postgis_full_version();</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>on both -- I bet they are running different versions of
proj.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>Details here.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial><A
href="http://postgis.refractions.net/pipermail/postgis-users/2008-January/018400.html">http://postgis.refractions.net/pipermail/postgis-users/2008-January/018400.html</A></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>It is a wonder my limited memory actually remembers these
things.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>Thanks,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial>Regina</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=272550020-20102010><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV><FONT color=#0000ff size=2
face=Arial></FONT><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of </B>Josh
Abts<BR><B>Sent:</B> Wednesday, October 20, 2010 3:28 PM<BR><B>To:</B> PostGIS
Users Discussion<BR><B>Subject:</B> Re: [postgis-users] ST_Transform Incorrect
Results?<BR></FONT><BR></DIV>
<DIV></DIV>Sure thing!<BR><BR>SRID 2163<BR>Server 1: "+proj=laea +lat_0=45
+lon_0=-100 +x_0=0 +y_0=0 +a=6370997 +b=6370997 +units=m +no_defs "<BR>Server 2:
"+proj=laea +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +a=6370997 +b=6370997 +units=m
+no_defs "<BR><BR>SRID 4326<BR>Server 1: "+proj=longlat +ellps=WGS84
+datum=WGS84 +no_defs "<BR>Server 2: "+proj=longlat +ellps=WGS84 +datum=WGS84
+no_defs "<BR><BR>Unless I am missing something, they both seem to be exactly
the same...<BR><BR>I found that earlier as well (forgot to include that as
well). But that really makes me think it is something with the version of
proj4 (or some data file it might be using?), but maybe someone has other
ideas?<BR><BR>
<DIV class=gmail_quote>On Wed, Oct 20, 2010 at 2:24 PM, Paul Ramsey <SPAN
dir=ltr><<A
href="mailto:pramsey@opengeo.org">pramsey@opengeo.org</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: rgb(204,204,204) 1px solid; MARGIN: 0pt 0pt 0pt 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Could you show the proj4text strings for your coordinate
systems? The<BR>srtext strings are actually just there for
decoration.<BR><BR>P<BR>
<DIV>
<DIV></DIV>
<DIV class=h5><BR>On Wed, Oct 20, 2010 at 12:16 PM, Josh Abts <<A
href="mailto:josh.abts@vistracks.com">josh.abts@vistracks.com</A>>
wrote:<BR>> As a followup, the following query reproduces the problem
exactly:<BR>><BR>> select
astext(st_transform(st_setsrid(st_makepoint(977119.259431679,<BR>>
-252548.899746532), 2163) ,4326))<BR>><BR>> On Server 1 the result is:
POINT(-88.11068 42.2810949683921)<BR>><BR>> On Server 2 the result is:
POINT(-88.11068 42.0896736466198)<BR>><BR>> It was also mentioned on
#postgis to include the differing srtext entries I<BR>> had found on the
two servers....<BR>><BR>> For SRID 4326:<BR>><BR>> Server 1 -
"GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS<BR>>
84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]"<BR>><BR>>
Server 2 - "GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS<BR>>
84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]"<BR>><BR>>
For SRID 2163:<BR>><BR>> Server 1 - "PROJCS["US National Atlas Equal
Area",GEOGCS["Unspecified datum<BR>> based upon the Clarke 1866
Authalic<BR>>
Sphere",DATUM["Not_specified_based_on_Clarke_1866_Authalic_Sphere",SPHEROID["Clarke<BR>>
1866 Authalic<BR>>
Sphere",6370997,0,AUTHORITY["EPSG","7052"]],AUTHORITY["EPSG","6052"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4052"]],PROJECTION["Lambert_Azimuthal_Equal_Area"],PARAMETER["latitude_of_center",45],PARAMETER["longitude_of_center",-100],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","2163"]]"<BR>><BR>>
Server 2 - "PROJCS["unnamed",GEOGCS["unnamed<BR>>
ellipse",DATUM["unknown",SPHEROID["unnamed",6370997,0]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Lambert_Azimuthal_Equal_Area"],PARAMETER["latitude_of_center",45],PARAMETER["longitude_of_center",-100],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1],AUTHORITY["EPSG","2163"]]"<BR>><BR>><BR>>
On Wed, Oct 20, 2010 at 11:14 AM, Josh Abts <<A
href="mailto:josh.abts@vistracks.com">josh.abts@vistracks.com</A>>
wrote:<BR>>><BR>>> Hello,<BR>>><BR>>> I have been
having a problem where I am getting mixed results from two<BR>>> servers
using the same dataset. The command I am running is as
follows:<BR>>><BR>>> select
astext(st_transform(start_point,<BR>>>
4326)),astext(st_transform(end_point, 4326)) from mytable where
gid=123<BR>>><BR>>> The two columns are originally using SRID 2163
so I am transforming them<BR>>> into 4326. But the results on one
server (correct) are different than the<BR>>> results on a second server
(incorrect). They are off by .2 latitude<BR>>>
roughly.<BR>>><BR>>> For example one result set is as
follows:<BR>>><BR>>> Server 1 (correct): "POINT(-88.11068
42.2810949683921)";"POINT(-88.10731<BR>>> 42.2844149305216)"<BR>>>
Server 2 (incorrect): "POINT(-88.11068
42.0896736466198)";"POINT(-88.10731<BR>>>
42.0929914612221)"<BR>>><BR>>> As you can see the longitudes are
correctly transformed, but the latitude<BR>>> is
not.<BR>>><BR>>> I have also included the postgis_full_version
output in case a version<BR>>> issue might be the
culprit.<BR>>><BR>>> Server 1: "POSTGIS="1.3.2"
GEOS="3.0.0rc4-CAPI-1.3.3" PROJ="Rel. 4.5.0, 22<BR>>> Oct 2006"
USE_STATS"<BR>>> Server 2: "POSTGIS="1.5.2" GEOS="3.2.2-CAPI-1.6.2"
PROJ="Rel. 4.7.1, 23<BR>>> September 2009" LIBXML="2.7.5" USE_STATS
(procs from 1.5 r5385 need<BR>>> upgrade)"<BR>>><BR>>> So
you can see I am using a newer version of PostGIS as well as Proj4
but<BR>>> I can't seem to figure out why this would result in an
incorrect<BR>>> St_Transform result.<BR>>><BR>>> I also
checked further into the spatial_ref_sys table on both servers and<BR>>>
Server 1 has slightly more detailed srtext but they have the same
proj4text<BR>>> lines. I tried copying the srtext from Server 1 to
Server 2 and there was<BR>>> no change.<BR>>><BR>>> The only
other difference would be the system platforms themselves which<BR>>>
are below.<BR>>><BR>>> Server 1: "PostgreSQL 8.3.4, compiled by
Visual C++ build 1400" (this is a<BR>>> windows 2003 server)<BR>>>
Server 2: "PostgreSQL 8.4.5 on x86_64-pc-linux-gnu, compiled by
GCC<BR>>> gcc-4.4.real (Ubuntu 4.4.1-4ubuntu9) 4.4.1,
64-bit"<BR>>><BR>>> Anyone have any ideas of what I could look
into to see why I might be<BR>>> getting this slight variation in
results? I can't find anything that would<BR>>> seem to be the
problem or cause of a varying transformation...<BR>>><BR>>>
Thanks!<BR>>> Josh<BR>><BR>><BR>><BR>> --<BR>> Joshua
Abts<BR>> IT Specialist<BR>> VisTracks, Inc.<BR>> <A
href="mailto:josh.abts@vistracks.com">josh.abts@vistracks.com</A><BR>>
(630) 596-5426<BR>><BR></DIV></DIV>>
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clear=all><BR>-- <BR>Joshua Abts<BR>IT Specialist<BR>VisTracks, Inc.<BR><A
href="mailto:josh.abts@vistracks.com">josh.abts@vistracks.com</A><BR>(630)
596-5426<BR></BODY></HTML>