FW: [Qgis-user] problems with layers from one source

[Gerardo Jimenez]

Gerardo Jiménez Delgado
Instituto de Investigaciones Antropológicas
Universidad Nacional Autónoma de México
Ciudad Universitaria s/n
Coyoacan 04510
Mexico City
Mexico

56 22 95 16

From: gejst5 at hotmail.com
To: caroline.t.rendon at gmail.com
Subject: RE: [Qgis-user] problems with layers from one source
Date: Sat, 17 Dec 2011 12:30:49 -0500







I am sorry to differ. They can not be in the same CRS. A latitutude longitude CRS has valus for longitud +- 180 and for latitude +- 90 Degrees. A crs such as a UTM (for instance) could have values in the 10,000 to less than a million for the east, and northings  could have values from 0 to almost 10,000,000. Then, your data could not share crs. If you change the crs in propertied/general/specify crs that aill not make any difference and could make the problems worst since, for instance, if your data is in the west hemisphere and you load data from a utm layer 
 as a latitude longitue crs ,  any GIS (not only qgis)all will be displace the layers, since utm do not handle negative values. In order that data could be in the same crs you have to reproject your data. Reprojecting converts from one crs to another totally different (from espherical coordinates to metric ones). For vector layers in qgis 1.7 you have the layer and chose save as, define the file format, choose the original crs and the one you want. For raster layers you have to go to raster/projections/war(reproject). In order to reproject, I insist, you must know the original crs of your data. 
Can you let us know where your data is located? also if you know the crs? also sometimes it is worth to know which version of Qgis you are using and in which OS you are using...
Hope it helps 

Gerardo Jiménez Delgado
Instituto de Investigaciones Antropológicas
Universidad Nacional Autónoma de México
Ciudad Universitaria s/n
Coyoacan 04510
Mexico City
Mexico

56 22 95 16

Date: Sat, 17 Dec 2011 10:33:17 -0600o select the laye
Subject: Re: [Qgis-user] problems with layers from one source
From: caroline.t.rendon at gmail.com
To: gejst5 at hotmail.com
CC: qgis-user at lists.osgeo.org

The CRS is the same for all my layers, this doesn't seem to change anything.

On Sat, Dec 17, 2011 at 7:06 AM, Gerardo Jimenez <gejst5 at hotmail.com> wrote:





The main problem could be that your layers are in different CRS. I assume that you want to use lat lon coordinates ("they should be in the range of (-87, 41)"). Because you can not have millions of degrees, it is pretty sure that the layers that display coordinates in the millions could be a CRS that defines its measuring units in meters or feets. For vector layers (and assuming a format that can store projection information), select the layer , right click, choose properties and go to the general tab. There you must be able to see the projection information. For raster layers go to rater menu,  choose Miscellaneous and select info. Choose your raster and you must be able to see the projection information there. 


I like to have all my layers in the same CRS, some people also likes to use the "on the fly CRS transformation" capability of QGIS . Try in Settings, project settings and go to the CRS tab, Choose "enable on the  fly CRS transformation", then load some layers. One  thing is for sure, you must know the crs of each of your layers before starting to work with them.


Hope it helps

Gerardo Jiménez Delgado
Instituto de Investigaciones Antropológicas
Universidad Nacional Autónoma de México
Ciudad Universitaria s/n
Coyoacan 04510
Mexico City
Mexico

56 22 95 16

Date: Fri, 16 Dec 2011 11:36:07 -0600
From: caroline.t.rendon at gmail.com
To: qgis-user at lists.osgeo.org

Subject: [Qgis-user] problems with layers from one source

Hello (again!) 
 
I'm having trouble with all the layers I download from one particular source. These layers don't show up in the same place as any others of the same area, including those I've geocoded myself. The coordinates shown at the bottom of the screen for these are HUGE - they should be in the range of (-87, 41) but they're in the millions. I've made sure all layers are in the correct CRS and done everything else I can think of. Does anyone have any tips or ideas? Thank you!



Caroline

_______________________________________________
Qgis-user mailing list
Qgis-user at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user 		 	   		  

_______________________________________________

Qgis-user mailing list

Qgis-user at lists.osgeo.org

http://lists.osgeo.org/mailman/listinfo/qgis-user



 		 	   		   		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20111217/64e82b76/attachment.html>