[postgis-users] couldn't get the correct projected values

[Andy Anderson]

On May 16, 2008, at 6:55 AM, Obe, Regina wrote:

> What is the SRID of your il_izmir3 geometry to begin with?
>
> If you imported it and incorrectly stated it as 32635 rather than  
> 4269 or 4326, then presumably the transform will do nothing since  
> it will see 32635 -> 32635 (you are already - nothing to do here).

Excellent idea! But if this is the case, shouldn't the first thing to  
do be to fix the original table:

	update il_izmir3 set the_geom = ST_SetSRID(the_geom, 4326);

and then Ahmet's original step 1 should work.

-- Andy

>
> I am going to guess that the SRID of your il_izmir3 is incorrectly  
> stated and that to fix, scrap the second statement and change your  
> first statement to  (note if your data is NAD83 longlat rather than  
> WGS long lat change the 4326 to 4269)
>
> create table izmir_il4 as select
> gid,il_kod,iladi,transform(ST_SetSRID(the_geom,4326),32635) as  
> the_geom from il_izmir3;
>
> or alternatively change your second statement to
>
> UPDATE izmir_il4 SET the_geom=Transform(ST_SetSRID(the_geom,4326), 
> 32635);
>
> Note its safer to recreate the table since who knows what  
> projection you stated the first as so you are still transforming a  
> guess to a guess.
>
> Hope that helps,
> Regina
>
>
>
> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net [mailto:postgis- 
> users-bounces at postgis.refractions.net] On Behalf Of Paragon  
> Corporation
> Sent: Friday, May 16, 2008 6:18 AM
> To: 'PostGIS Users Discussion'
> Subject: RE: [postgis-users] couldn't get the correct projected values
>
> You are confusing setsrid with transform.
>
> Remember setsrid - doesn't change the geometry it simple certifies  
> that a
> geometry is of a particular projection - basically
>
> I am because I say I am
>
>
> Transform - moves a geometry from one projection to another
>
> I am not , but please make me so.  Of course the please make me so  
> will fail
> if you don't know what it is  to begin with
>
>
> So all being said, your statement 2 is wrong and should be
>
> update izmir_il4 set the_geom=Transform(the_geom,32635);
>
> Hope that helps,
> Regina
>
> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net
> [mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of  
> orkun
> Sent: Friday, May 16, 2008 4:00 AM
> To: postgis-users at postgis.refractions.net
> Subject: [postgis-users] couldn't get the correct projected values
>
> hello
>
> whatever I have done, I couldn't get the correct projected values  
> in postgis
> environment.
>
> 1. # lon/lat to utm projection
>
> create table izmir_il4 as select
> gid,il_kod,iladi,transform(the_geom,32635) as the_geom from il_izmir3;
>
> 2.
> update izmir_il4 set the_geom=setsrid(the_geom,32635);
>
> 3.
>
> select extent(the_geom) from izmir_il4;
>
> extent
> ---------------------------------------------------------------------- 
> ----
> BOX(26.2226982116699 37.8668251037598,28.4587249755859  
> 39.3925666809082)
>
> but these are not utm values. They are still in lon/lat values
>
> I checked extent values with proj values. I got correct values:
>
> echo "26.2226982116699 37.8668251037598" | proj +proj=utm +zone=35
> +ellps=WGS84 +datum=WGS84
> 431631.23       4191323.84
> orkun at orkun-desktop:/usr/local/izmir/veri/izmir3$ echo  
> "28.4587249755859
> 39.3925666809082" | proj +proj=utm +zone=35 +ellps=WGS84 +datum=WGS84
> 625615.27       4361356.53
>
>
> how can get values generated from "proj" in postgis environment ?
> what am I doing wrong ?
>
> here is the srid values of 32635 :
> 32635 | +proj=utm +zone=35 +ellps=WGS84 +datum=WGS84 +units=m +no_defs
>
> regards
>
> --
> Ahmet Temiz
> Jeo. Müh.
> Afet Isleri Gen. Md.lügü
> Deprem Ar. D.
>
> Ahmet Temiz
> Geo. Eng.
> General Dir. of
> Disaster Affairs
>
>
>
> -- 
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
>
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>
>
>
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
> -----------------------------------------
> The substance of this message, including any attachments, may be
> confidential, legally privileged and/or exempt from disclosure
> pursuant to Massachusetts law. It is intended
> solely for the addressee. If you received this in error, please
> contact the sender and delete the material from any computer.
>
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users