[postgis-users] Need Help with Transform

[R H]

Thanks Regina that is it, I didn't have the right projection to begin with.
I needed NAD_1983_StatePlane_Nevada_East_FIPS_2701_Feet
and I was using NAD83 / Nevada East 
 
The projection I needed wasn't in the default spatial_ref_sys?  I assumed all of the srid's would be in there, I guess not?  I was able to find it at http://spatialreference.org and I inserted into spatial_ref_sys.  Now it is working as expected.
 
Thanks again.> Subject: RE: [postgis-users] Need Help with Transform> Date: Thu, 11 Sep 2008 15:07:47 -0400> From: robe.dnd at cityofboston.gov> To: postgis-users at postgis.refractions.net> > RH,> > I'm not aware of an easy way to tell if its in range (I think you can> from the proj4text lon a b blah blah blah args) defined in> spatial_ref_sys, but I'm not that technically savvy.> > If you get something like all the same long lat when you project back> to 4326 (WGS 84), or you get weird numbers like 135, 90 etc. then its> probably wrong.> > Given that all your below seem to project to below - I would say you are> wrong> POINT(-115.583333333333 90)> > First of all when I look in spatial ref> > SELECT srtext from spatial_ref_sys where srid = 32107 > > I get the below> "PROJCS["NAD83 / Nevada> East",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS> 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","> 6269"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0> 1745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4269"]],PRO> JECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",34.75],PAR> AMETER["central_meridian",-115.5833333333333],PARAMETER["scale_factor",0> .9999],PARAMETER["false_easting",200000],PARAMETER["false_northing",8000> 000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","32107"]]> "> > so if you know your data is not in Nevada - you guessed wrong about the> spatial reference system> > > Well even if its in the range doesn't necessarily mean you have the> right projection. > > The trick I normally use when I have no clue what projection a data set> is in but I have some guesses e.g. I know its a meter projection or the> state etc) and I know say the long lat of a point that should be in that> range would be something like below (and that usually 0s down to 1 or 2> likely candidates). If the projection doesn't exist in spatial_ref_sys> (or I have the ESRI .prj file) - then I go to> http://spatialreference.org and do some searches and load up some likely> culprits in my spatial_ref_sys table and retry the below db or upload> the prj to spatial ref.> > SELECT srid, srtext, proj4text> FROM spatial_ref_sys > WHERE proj4text ILIKE '%units=m%' AND srtext ILIKE '%NAD%' > AND ST_Transform(ST_SetSRID(ST_MakePoint(-71.015,42.372), 4326), srid)> && > ST_Expand(ST_SetSRID(ST_MakePoint(239898, 902552), srid),1000)> > > Hope that helps,> Regina> ________________________________> > From: postgis-users-bounces at postgis.refractions.net> [mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of R H> Sent: Thursday, September 11, 2008 11:42 AM> To: PostGIS Users Discussion> Subject: RE: [postgis-users] Need Help with Transform> > > Thanks for the Help Regina, below are some of the points I attempted.> > setsrid(MakePoint(834934.2263,26712690.6089, 32107) > setsrid(MakePoint(834533.210694,26712881.1962, 32107) > setsrid(MakePoint(834224.086891,26712318.3331, 32107) > > Is there a way to check if it is in the range of the projection? > > > > ________________________________> > > From: lr at pcorp.us> To: postgis-users at postgis.refractions.net> Subject: RE: [postgis-users] Need Help with Transform> Date: Fri, 5 Sep 2008 18:19:58 -0400> > > > RH,> > This kind of thing happens if your input points are not actually in the> projection you say they are with setsrid.> > Give us an example 32107 point you are using. I suspect it doesn't fall> in the range of a valid 32107 point.> > Hope that helps,> Regina> > ________________________________> > From: postgis-users-bounces at postgis.refractions.net> [mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of R H> Sent: Friday, September 05, 2008 1:13 PM> To: postgis-users at postgis.refractions.net> Subject: [postgis-users] Need Help with Transform> > > > > ________________________________> > > Transform is returning to the same value, for different inputs? Below> is what I have done...> > select AddGeometryColumn('data_stage', 'table', 'geo4269', 4269,> 'POINT', 2)> select AddGeometryColumn('data_stage', 'table', 'geo32107', 32107,> 'POINT', 2)> > update table> set geo32107= setsrid(MakePoint(x, y), 32107) > where ....> > update table set geo4269 = transfrom(geo32107, 4269)> where ....> > column geo4269 all have the same vaule. select AsText(geo4269) returns> 'POINT(-115.583333333333 90)' for all rows. And select AsText(geo32107)> returns the point as input.> > Am I using transform wrong? Or any other problems? Any help many> thanks...> > > > > -----------------------------------------> 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
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