<div dir="ltr"><div>Thanks Nathan,<br><br>I see where you're coming from, but it's not working. The regex selects all values. I wonder if the problem lies in the data table? The column format is 'real' and I generated the column using the zonal statistics plugin from an underlying raster overlain with a regular grid. Null values seem to have been produced for cells outside the raster, with nan produced where the raster has no data.<br>
<br>I recoded the raster output from grass to classify the no data values as -999. How do I go about selecting these? I thought "column" < 0 would work, but this doesn't select anything.<br><br></div>Another option could be to use the raster tool and vectorise it, unfortunately this doesn't produce a whole grid as it only outputs integer values and joins some cells together.<br>
</div><div class="gmail_extra"><br><br><div class="gmail_quote">On 27 September 2013 13:44, Nathan Woodrow <span dir="ltr"><<a href="mailto:madmanwoo@gmail.com" target="_blank">madmanwoo@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hey Michael,<div><br></div><div>Try this expression using the advanced selection feature:</div><div><br>
</div><div>regexp_match('column', '\\d*') = 1<br></div><div><br></div><div>This is using a regex to match column as any number of digits (\\d*). If it's not a digit it will return 0 so you want to only select the ones that = 1.</div>
<div><br></div><div>- Nathan</div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div class="h5">On Fri, Sep 27, 2013 at 10:16 PM, Michael Spencer <span dir="ltr"><<a href="mailto:spencer.mike.r@gmail.com" target="_blank">spencer.mike.r@gmail.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div dir="ltr"><div><div><div><div><div>
Date: Thu, 26 Sep 2013 18:18:10 +0200<br>
From: Bernhard Str?bl <<a href="mailto:bernhard.stroebl@jena.de" target="_blank">bernhard.stroebl@jena.de</a>><div><br>
<br>
Hi,<br>
<br>
Am <a href="tel:26.09.2013%2018" value="+12609201318" target="_blank">26.09.2013 18</a>:07, schrieb Michael Spencer:<br>
> Having a strange problem at the moment.<br>
><br>
> If I open a vector attribute table and click on a column heading to sort<br>
> the column then this doesn't seem to work. The column contains mainly<br>
> numbers with some NA and some NULL strings.<br>
><br>
> The sort action groups most together most NA and NULL, and orders the<br>
> numbers, but some strings slip through the gaps and appear where they<br>
> aren't wanted in the number sequence!<br>
><br>
> I'm working in QGIS 2.0.1 on Ubuntu 12.04.<br>
><br>
> The reason I want to do this is to delete all records that aren't<br>
> numeric, so if there's a neater way to accomplish this that would be great!<br>
<br>
A neater way would be to select the records in question and then simply<br>
delete the selected. Hint select for nulls with<br>
<code>"my_field" is null</code><br><br></div></div>Thanks Bernhard, this was my original choice. Unfortunately I find the select tool a total black box and can't get my head around it. Your suggestion works for entries with 'null' in, but I can't get a response when I want to select 'nan' values. I've tried as:<br>
<br></div><"field" is nan><br></div><"field" is 'nan'><br></div><div><"field" = 'nan'><br></div><div><br></div>Both with no joy. Is there a crib sheet somewhere with basic options on?<br>
<br></div>Ta,<br>Michael<br><div><div><div><div><div><div>
<br>
Bernhard<br>
<br>
><br>
> Ta,<br>
> Michael</div></div></div></div></div></div></div>
<br></div></div>_______________________________________________<br>
Qgis-user mailing list<br>
<a href="mailto:Qgis-user@lists.osgeo.org" target="_blank">Qgis-user@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/qgis-user" target="_blank">http://lists.osgeo.org/mailman/listinfo/qgis-user</a><br></blockquote></div><br></div>
</blockquote></div><br></div>