[Qgis-user] Why does clipping a raster alters cell size? (Luciano La Sala)

Michael Treglia mtreglia at gmail.com
Wed May 20 10:17:14 PDT 2015


Hi Luciano,
glad it worked now - the latest version is 2.8.2 ('Wien')
http://www.qgis.org/en/site/forusers/download.html
best,
mike

On Wed, May 20, 2015 at 12:11 PM, Luciano La Sala <
lucianolasala at yahoo.com.ar> wrote:

> Hola Mike,
>
> Thanks! Adding the extension myself did work! The has to be something
> wrong either with my OS or my version of QGIS. By the way, I am using the
> latest version of QGIS (2.2.0 Valmiera).
>
> Best,
>
> Luciano
>
> El 5/20/2015 a las 1:47 PM, Michael Treglia escribió:
>
>> Hi Luciano,
>>
>> I'm bringing this back to the list so others can chime in and follow
>> this thread in the future.
>>
>> Strange that the file isn't writing out with the .asc extension (it does
>> for me) - what version of QGIS are you using?
>>
>> A very simple solution: simply rename the file to add the '.asc'
>> extension. (Right click on the file name in Windows Explorer, select
>> 'Rename', and at the end of the filename simply add '.asc') - again ,
>> this should be with the Windows setting to have file extensions visible.
>>
>> Hope that helps
>> mike
>>
>>
>> On Wed, May 20, 2015 at 11:30 AM, Luciano La Sala
>> <lucianolasala at yahoo.com.ar <mailto:lucianolasala at yahoo.com.ar>> wrote:
>>
>>     Hi Mike,
>>
>>     Many thanks for the response. Your assumption about the content of
>>     my file is correct. This seems to be the .asc file that I need. I
>>     did follow your instructions and unchecked the box next to "Hide
>>     extensions for known file types". Now, two of the three files show
>>     their extension, namely .aux.xml and .prj. However, the suspected
>>     .asc file still shows no extension. Also, when I look at the file in
>>     Windows Explorer, under the detail view, there is no extension for
>>     the file! Finally, when right-click on the file, go to Properties
>>     and then under General >> Type of file: FILE, and under Details >>
>>     Type: File. No extension whatsoever!
>>
>>     I did a quick search on the web and I found that the FILE file type
>>     is primarily associated with 'File With No Extension'. If you are
>>     seeing the file type FILE this is not a file extension but an
>>     indicator in Windows Explorer that the file has not file extension.
>>     Incorrect file associations could be the result of underlying issues
>>     within the PC system.
>>
>>     This is very frustrating since I need those .asc files to model my
>>     species distribution models using maxent.
>>
>>     Ideas?
>>
>>     Best,
>>
>>     Luciano
>>
>>
>>     El 5/20/2015 a las 12:50 PM, Michael Treglia escribió:
>>
>>         Hi Luciano,
>>
>>         the file that can be opened in notepad is probably has a header of
>>         something like:
>>         ncols
>>         nrows
>>         xllcorner
>>         yllcorner
>>         cellsize
>>         NODATA_value
>>
>>         Followed by the values from your raster next, right?
>>
>>         If so, that is the .asc file that you want - when I export the
>>         .asc file
>>         (running QGIS 2.8.1 x64 on Win 7), it exports these files
>> correctly,
>>         with the appropriate extension. (Though in the file Explorer, if
>>         you are
>>         viewing the
>>
>>         On Windows [not sure about other OSs], the file extension (.asc)
>>         is not
>>         shown by default, for files that Windows knows how to open.  To
>>         change
>>         this, you would go to Control Panel -> [view by icons] ->Folder
>>         Options
>>         -> View Tab, and un-check the box next to 'Hide extensions for
>> known
>>         file types'.  Also, if when you are looking at the available
>>         files in
>>         Windows Explorer, if you change to the detail view (which has
>>         file size,
>>         date modified, etc.), there should be a field "Type", for which
>> this
>>         file should be specified as a "ASC" file
>>
>>         Hope this helps and works for you.
>>
>>         Best
>>         mike
>>
>>
>>         On Wed, May 20, 2015 at 10:21 AM, Luciano La Sala
>>         <lucianolasala at yahoo.com.ar <mailto:lucianolasala at yahoo.com.ar>
>>         <mailto:lucianolasala at yahoo.com.ar
>>
>>         <mailto:lucianolasala at yahoo.com.ar>>> wrote:
>>
>>              Thank you very much Nicolas for your response. I have no
>>         idea how to
>>              use use the -tr xres yres switch in gdalwarp.
>>              However, I solved the problem using GDAL's algorithm "Clip
>>         raster by
>>              mask layer" and by seting the option "Keep resolution of
>> output
>>              raster" to "Yes". That produced a .tif file with equal
>>         pixel size
>>              (200, -200).
>>
>>              Following, I convert this GeoTIFF to .ASC format using:
>>         "Raster >
>>              Conversion > Translate (Convert format)" and the setting
>>         the Output
>>              file to [GDAL] Arc/Info ASCII Grid (*.asc *.ASC).
>>
>>              The result is three files: the auxiliary file .aux, the
>>         coordinate
>>              system file .prj, and one more filename of File type FILE
>>         that can
>>              be opened with Notepad. Disappointingly, no .asc file was
>>         created.
>>              What am I doing wrong? I need .asc files of my environmental
>>              variables to be later processed using other software.
>>
>>              Thanks!
>>
>>
>>
>>              El 5/20/2015 a las 6:02 AM,
>>         qgis-user-request at lists.osgeo.org
>>         <mailto:qgis-user-request at lists.osgeo.org>
>>              <mailto:qgis-user-request at lists.osgeo.org
>>         <mailto:qgis-user-request at lists.osgeo.org>> escribió:
>>
>>                  Send Qgis-user mailing list submissions to
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>>
>>         <mailto:qgis-user-owner at lists.osgeo.org>>
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>>
>>                  Today's Topics:
>>
>>                       1. Re: Error installing QGIS 2.8.2-1 on Mac
>>         (Jacopo Tonetti)
>>                       2. Draw square or line and see meters (elmalle)
>>                       3. Re: Error installing QGIS 2.8.2-1 on Mac (Jes?s)
>>                       4. Re: Error installing QGIS 2.8.2-1 on Mac (William
>>                  Kyngesburye)
>>                       5. Why does clipping a raster alters cell size?
>>         (Luciano La
>>                  Sala)
>>                       6. Re: Why does clipping a raster alters cell size?
>>                  (Nicolas Cadieux)
>>                       7. How I create web gis through Qgis (Debajyoti
>> Ghosh)
>>                       8. Re: new issue with raster calculator (Bernd
>>         Vogelgesang)
>>                       9. Re: How I create web gis through Qgis (McDonaldR)
>>
>>
>>
>>
>> ----------------------------------------------------------------------
>>
>>                  Message: 1
>>                  Date: Tue, 19 May 2015 22:23:33 +0200
>>                  From: Jacopo Tonetti <jacopotonetti at gmail.com
>>         <mailto:jacopotonetti at gmail.com>
>>                  <mailto:jacopotonetti at gmail.com
>>         <mailto:jacopotonetti at gmail.com>>>
>>                  To: Jes?s <jesusl.temez at gmail.com
>>         <mailto:jesusl.temez at gmail.com> <mailto:jesusl.temez at gmail.com
>>         <mailto:jesusl.temez at gmail.com>>>
>>                  Cc: qgis-user at lists.osgeo.org
>>         <mailto:qgis-user at lists.osgeo.org>
>>         <mailto:qgis-user at lists.osgeo.org
>>         <mailto:qgis-user at lists.osgeo.org>>
>>                  Subject: Re: [Qgis-user] Error installing QGIS 2.8.2-1
>>         on Mac
>>                  Message-ID:
>>
>>
>>         <
>> CAJnh74mJHzhAJEnXJ6PmQ_UQf_n04p5OnMZONg8UJMwYREaN2Q at mail.gmail.com
>>         <mailto:
>> CAJnh74mJHzhAJEnXJ6PmQ_UQf_n04p5OnMZONg8UJMwYREaN2Q at mail.gmail.com>
>>
>>         <mailto:
>> CAJnh74mJHzhAJEnXJ6PmQ_UQf_n04p5OnMZONg8UJMwYREaN2Q at mail.gmail.com
>>         <mailto:
>> CAJnh74mJHzhAJEnXJ6PmQ_UQf_n04p5OnMZONg8UJMwYREaN2Q at mail.gmail.com>>>
>>                  Content-Type: text/plain; charset="iso-8859-1"
>>
>>                  Hi, seems that you have an older version of PROJ
>>         library. Did
>>                  you download
>>                  the package or install via homebrew? I recommend the
>>         latter (but
>>                  you should
>>                  use command line), I followed this
>>
>>         <
>> https://github.com/OSGeo/homebrew-osgeo4mac/wiki/Developing-on-QGIS-using-OSGeo4Mac
>> >
>>                  guide and everything is fine, same OS and version of
>> QGIS.
>>                  j
>>
>>                  2015-05-19 19:38 GMT+02:00 Jes?s
>>         <jesusl.temez at gmail.com <mailto:jesusl.temez at gmail.com>
>>                  <mailto:jesusl.temez at gmail.com
>>
>>         <mailto:jesusl.temez at gmail.com>>>:
>>
>>
>>                      Trying to install 2.8.2-1 on a Mac (10.9.5) I find
>>         this error:
>>
>>                      Dyld Error Message:
>>                          Library not loaded:
>>                      /Library/Frameworks/PROJ.framework/Versions/4/PROJ
>>                          Referenced from:
>>         /Applications/QGIS.app/Contents/MacOS/QGIS
>>                          Reason: Incompatible library version: QGIS
>> requires
>>                      version 10.0.0 or
>>                      later, but PROJ provides version 8.0.0
>>
>>                      Binary Images:
>>                            0x7fff6810f000 -     0x7fff68142817  dyld
>> (239.4)
>>                      <7AD43B9B-5CEA-3C7E-9836-A06909F9CA56> /usr/lib/dyld
>>                            0x7fff8bc7f000 -     0x7fff8bc7ffff
>>                      com.apple.ApplicationServices (48
>>                      -
>>                      48) <3E3F01A8-314D-378F-835E-9CC4F8820031>
>>
>>
>>
>> /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Applicat
>>                      ionServices
>>                            0x7fff8bc9f000 -     0x7fff8bd0bfff
>>                      com.apple.framework.IOKit (2.0.1 -
>>                      907.100.14) <10932113-9F7E-38A0-A158-A019A555CAC3>
>>
>>         /System/Library/Frameworks/IOKit.framework/Versions/A/IOKit
>>                            0x7fff8dd59000 -     0x7fff8df3efff
>>                      com.apple.CoreFoundation (6.9 -
>>                      855.17) <729BD6DA-1F63-3E72-A148-26F21EBF52BB>
>>
>>
>>
>> /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundatio
>>                      n
>>
>>                      I delete old version first but I can't open new
>>         version when
>>                      finishing the
>>                      installation. I got this message: Qgis can't be
>>         open due to
>>                      a problem.
>>
>>                      Any idea? Thanks
>>                      Jesus
>>
>>
>>                      _______________________________________________
>>                      Qgis-user mailing list
>>         Qgis-user at lists.osgeo.org <mailto:Qgis-user at lists.osgeo.org>
>>         <mailto:Qgis-user at lists.osgeo.org
>>         <mailto:Qgis-user at lists.osgeo.org>>
>>         http://lists.osgeo.org/mailman/listinfo/qgis-user
>>
>>
>>
>>
>>
>>              --
>>              Luciano F. La Sala
>>              Consejo Nacional de Investigaciones Científicas y Técnicas
>>         (CONICET)
>>              Cátedra de Epidemiología
>>              Departamento de Biología, Bioquímica y Farmacia
>>              Universidad Nacional del Sur
>>              San Juan 670
>>              Bahía Blanca (8000)
>>              Argentina
>>              _______________________________________________
>>              Qgis-user mailing list
>>         Qgis-user at lists.osgeo.org <mailto:Qgis-user at lists.osgeo.org>
>>         <mailto:Qgis-user at lists.osgeo.org
>>         <mailto:Qgis-user at lists.osgeo.org>>
>>         http://lists.osgeo.org/mailman/listinfo/qgis-user
>>
>>
>>
>>     --
>>     Luciano F. La Sala
>>     Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
>>     Cátedra de Epidemiología
>>     Departamento de Biología, Bioquímica y Farmacia
>>     Universidad Nacional del Sur
>>     San Juan 670
>>     Bahía Blanca (8000)
>>     Argentina
>>
>>
>>
> --
> Luciano F. La Sala
> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
> Cátedra de Epidemiología
> Departamento de Biología, Bioquímica y Farmacia
> Universidad Nacional del Sur
> San Juan 670
> Bahía Blanca (8000)
> Argentina
>
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