<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /></head><body style='font-size: 10pt; font-family: Verdana,Geneva,sans-serif'>
<p>Hi Marco,</p>
<p>Thanks - now that I know that I need to enter the SRID with the "EPSG:" prefix, and that I need to use -1 in the Source Datum transformation I can confirm that it works.</p>
<p>It would be great, if somewhere in the metadata it would be visible that this file is now displayed using the nadgrids/GSB file. Otherwise, I have just to blindly trust, that QGIS does the right thing - which is a bit scary.</p>
<p>Do you think it would be possible to add a note in the metadata or general section of the layer properties confirming that QGIS is using a datum transformation to display this file?</p>
<p>I will make sure that the documentation will be improved regarding the global settings of the datum transformations.</p>
<p>Thanks,<br />Andreas</p>
<p>On 2016-10-04 13:17, Marco Hugentobler wrote:</p>
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0"><!-- html ignored --><!-- head ignored --><!-- meta ignored -->
<div class="moz-cite-prefix">Hi Andi<br /><br /> >1. As far as I understand, I have to copy the gsb file to the directory where proj stores the gsb files, in my case "C:\Program Files\OSGeo4W64\share\proj". Alternatively, one could set another folder >and adjust the PROJ_LIB env variable accordingly.<br /><br /> That should work<br /><br /><br /> to 2. and 3. : In the option dialog, you enter the datum transformation id of the datum transformation(s), not the proj parameter.<br /> So to get from epsg:21781 to epsg:2056 with CHENYX06a.gsb, you enter:<br /><br /> Source crs: EPSG:21781 <br /> Destination crs: EPSG:2056, <br /> Source datum transformation: 100001<br /> Destination datum transformation: -1<br /><br /> An easier way to get to these numbers is to check the box 'Ask for datum transformations if no default is defined'. Then add a layer in 21781 to the map and transform it to 2056 on-the-fly. In the dialog asking for the datum transformation, check 'Remember selection'. The entry will then appear in the options dialog.<br /><br /> Regards,<br /> Marco<br /><br /> On 10/04/16 12:58, Neumann, Andreas wrote:</div>
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">
<p>Hi,</p>
<p>I am struggling in QGIS 2x with datum transformations.</p>
<p>The manual is not explicit how to handle this correctly.</p>
<p>Here are the steps I tried:</p>
<p>1. As far as I understand, I have to copy the gsb file to the directory where proj stores the gsb files, in my case "C:\Program Files\OSGeo4W64\share\proj". Alternatively, one could set another folder and adjust the PROJ_LIB env variable accordingly.</p>
<p>2. In "Settings" --> "Options" --> "CRS" I can define default datum transformations. I tried to enter 21781 (Source CRS), 2056 (Destination CRS), +nadgrids=CHENYX06a.gsb (Source datum transfomation). Destionation datum has been left empty.</p>
<p>3. I would expect that whenever this combination 21781 --> 2056 shows up that QGIS would ask me to pick one the defaults specified in 2.</p>
<p>The problem is that 2. does not work. When I close the dialogue and reopen it, my modifications are gone ... and I never have the chance to select my datum transformation option.</p>
<p>Can you help me what I am doing things wrong?</p>
<p>Thank you,</p>
<p>Andreas</p>
<div> </div>
<br /><fieldset class="mimeAttachmentHeader"></fieldset><br />
<pre>_______________________________________________
Qgis-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Qgis-user@lists.osgeo.org">Qgis-user@lists.osgeo.org</a>
List info: <a class="moz-txt-link-freetext" href="http://lists.osgeo.org/mailman/listinfo/qgis-user">http://lists.osgeo.org/mailman/listinfo/qgis-user</a>
Unsubscribe: <a class="moz-txt-link-freetext" href="http://lists.osgeo.org/mailman/listinfo/qgis-user">http://lists.osgeo.org/mailman/listinfo/qgis-user</a></pre>
</blockquote>
<br />
<p> </p>
<pre class="moz-signature">--
Dr. Marco Hugentobler
Sourcepole - Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
<a class="moz-txt-link-abbreviated" href="mailto:marco.hugentobler@sourcepole.ch">marco.hugentobler@sourcepole.ch</a> <a class="moz-txt-link-freetext" href="http://www.sourcepole.ch">http://www.sourcepole.ch</a></pre>
<!-- html ignored --><br />
<div class="pre" style="margin: 0; padding: 0; font-family: monospace">_______________________________________________<br /> Qgis-user mailing list<br /><a href="mailto:Qgis-user@lists.osgeo.org">Qgis-user@lists.osgeo.org</a><br /> List info: <a href="http://lists.osgeo.org/mailman/listinfo/qgis-user">http://lists.osgeo.org/mailman/listinfo/qgis-user</a><br /> Unsubscribe: <a href="http://lists.osgeo.org/mailman/listinfo/qgis-user">http://lists.osgeo.org/mailman/listinfo/qgis-user</a></div>
</blockquote>
<p> </p>
<div> </div>
</body></html>