[postgis-users] problem to transform coordinates

[Obe, Regina]

I get the same wrong answer so your install is fine.  

I don't think your coordinates are in 22523.  They seem to be truncated
and flipped.
 
For example
Select ST_AsText(ST_Transform(ST_GeomFromText('POINT(-45
-20.65)',4326),22523 ))
 
Gives me 
POINT(500024.031982543 7716597.82168034)
 
So its like your coordinates are flipped and then divided by 1000 or
something
 
Assuming that is what is happening - then your point should be
- POINT(500290 7650676)
 
SELECT ST_AsText(ST_Transform(ST_GeomFromText('POINT(500290
7650676)',22523), 4326))

Which would give me 

POINT(-44.9974366430774 -21.2456507664743)

Is that more like what you were expecting for an answer?

Hope that helps,
Regina

________________________________

From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of
Felipe Fedel Pinto
Sent: Monday, August 04, 2008 10:49 AM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] problem to transform coordinates


SELECT ST_AsText(coord_22523)
FROM coordsformiga limit 2; 
return:
        st_astext        
-------------------------
 POINT(7650.676 500.29)
 POINT(7624.401 592.751)
(2 rows)



SELECT ST_AsText(ST_Transform(coord_ 

	22523, 4326))
	FROM coordsformiga limit 2;

return:
                 st_astext                 
-------------------------------------------
 POINT(140.139757378998 -89.9975973774248)
 POINT(140.139757378998 -89.9975973774248)
(2 rows)


SELECT postgis_full_version();
                               postgis_full_version

------------------------------------------------------------------------
----------
 POSTGIS="1.3.3" GEOS="3.0.0-CAPI-1.4.1" PROJ="Rel. 4.6.0, 21 Dec 2007"
USE_STATS
(1 row)





On Mon, Aug 4, 2008 at 10:20 AM, Obe, Regina <robe.dnd at cityofboston.gov>
wrote:


	Felipe Fedel,
	
	Can you send a sample of your data - results of the 2 queries
below
	
	SELECT ST_AsText(coord_22523)
	FROM coordsformiga limit 2;
	
	-- and result you get when you do
	SELECT ST_AsText(ST_Transform(coord_22523, 4326))
	FROM coordsformiga limit 2;
	
	Also what does
	
	SELECT postgis_full_version();
	
	give
	
	Only thought I have that could be wrong is your coordinates are
not
	really 22523 or there is a problem with your proj 4 install. The
above
	queries should pinpoint that.
	

	Hope that helps,
	Regina
	
	________________________________
	
	From: postgis-users-bounces at postgis.refractions.net
	[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf
Of
	Felipe Fedel Pinto
	
	Sent: Monday, August 04, 2008 9:27 AM
	To: PostGIS Users Discussion
	Subject: Re: [postgis-users] problem to transform coordinates
	


	it also happens when I use ST_Transform and return the same
thing from
	SELECT proj4text FROM spatial_ref_sys WHERE srid = 22523;
	
	
	Do you have another idea??
	
	Thanks!!!!
	
	Felipe Fedel
	
	On Thu, Jul 31, 2008 at 1:13 AM, Paragon Corporation
<lr at pcorp.us>
	wrote:
	
	
	       Maybe there is something wrong with your entry in the
	spatial_ref_sys table for that SRID.  Also provide two sample
22523
	points and what the ST_Transform looks like.
	
	       Also please use ST_Transform if you are using a PostGIS
install
	> 1.2
	
	       What does
	
	       SELECT proj4text
	       FROM spatial_ref_sys
	       WHERE srid = 22523
	
	       give you?
	
	       Mine gives
	       +proj=utm +zone=23 +south +ellps=intl
	+towgs84=-206,172,-6,0,0,0,0 +units=m +no_defs
	
	       Hope that helps,
	       Regina
	
	________________________________
	
	       From: postgis-users-bounces at postgis.refractions.net
	[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf
Of
	Felipe Fedel Pinto
	       Sent: Wednesday, July 30, 2008 7:26 PM
	       To: postgis-users at postgis.refractions.net
	       Subject: [postgis-users] problem to transform coordinates
	
	
	       To transform coordinates in PostGis I use the followed
function:
	
	       UPDATE <table> SET <new_geometry_column> =
	transform(<original_geometry_column>,<new_SRID>);
	
	       I have been having a weird problem when I try to
transform
	coordinates that are in a SRID=22523.
	       Ex: I have to transform them to a SRID=4326
	
	       UPDATE coordsformiga SET coord_4326 =
	transform(coord_22523,4326);
	
	       where coordsformiga is the table,
	                 coord_22523 is the original geometry column
with the
	coordinates in a SRID=22523
	                 coord_4326 I'd be the geometry column with the
	coordinates transformed in a SRID=4326
	
	       the problem is:
	       After the function, in the geometry column (coord_4326),
all of
	the 97 coordinates have the same values.
	       But it's happening only with a SRID=22523.
	
	       Anybody knows what is happening??
	
	       thanks
	
	
	
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