<HTML><HEAD></HEAD>
<BODY dir=ltr>
<DIV dir=ltr>
<DIV style="FONT-FAMILY: 'Calibri'; COLOR: #000000; FONT-SIZE: 12pt">
<DIV
style="FONT-STYLE: normal; DISPLAY: inline; FONT-FAMILY: 'Calibri'; COLOR: #000000; FONT-SIZE: small; FONT-WEIGHT: normal; TEXT-DECORATION: none">
<DIV dir=ltr>
<DIV style="FONT-FAMILY: 'Calibri'; COLOR: #000000; FONT-SIZE: 12pt">
<DIV>Hi All,</DIV>
<DIV> </DIV>
<DIV>I have been trying to translate a series of practical exercises to teach
marine biologists from ArcGIS into QGIS to help promote use QGIS in marine
biology as an alternative to commercial GIS sofftware. However, I have run
into a problem with one particular step in my standard training exercises.
</DIV>
<DIV> </DIV>
<DIV>This step involves creating a vector grid with the vector grid tool, and
then using the union tool to divide the vector grid cells into sections which
are on land and on water, so the land portions can be removed (leaving just the
portions which are in the sea – this allows for the calculation of the area of
each vector grid cell which is covered in water and use it to correct for
various biases this can introduce in analyses).</DIV>
<DIV> </DIV>
<DIV>When working with QGIS 2.2 and 2.4, this process worked more or less
perfectly, but in 2.6, I am having a intermittent problem where it will work on
some occasions but not on others, using what should be more or less identical
data layers and identical settings. When it doesn’t work, the Union tool hangs
at a specific percentage (in this case 23%), and there is an error messsage
which says: Feature Geometry Not Imported (OGR Error:).</DIV>
<DIV> </DIV>
<DIV>I don’t know if it makes any difference, but I am using a user-defined
coordinate reference sytem that is based on a transverse mercator projecton fr
both the project and the input data layers for the union tool (this seemed to
cause some problems in earlier versoins of QGIS, but work arounds were
possible).</DIV>
<DIV> </DIV>
<DIV>Can anyone offer advice as to what might be going on here and how to get
round this issue? I can provide sample data layers on request.</DIV>
<DIV> </DIV>
<DIV>The system which this problem is occurring on is a laptop running Windows
8.1 and QGIS 2.6.</DIV>
<DIV> </DIV>
<DIV>I am keen to try to find some sort of solution to this as this is a
standard process for marine biologists, and being unable to do it would limit
the ability to work with QGIS as an alternative to commercial GiS
software.</DIV>
<DIV> </DIV>
<DIV>Thanks for any advice which can be provided.</DIV>
<DIV> </DIV>
<DIV>All the best,</DIV>
<DIV> </DIV>
<DIV>Colin</DIV>
<DIV> </DIV>
<DIV
style="FONT-FAMILY: 'Calibri'; COLOR: #000000; FONT-SIZE: 12pt">==================================================================================<BR>GIS
IN ECOLOGY - Providing Training, Advice And Consultancy On The Use Of GIS In
Ecology<BR><BR>Web: www.GISinEcology.com Email:
info@GISinEcology.com<BR><BR>Need to ask a question about using GIS? Try the GIS
In Ecology Forum: www.GISinEcology.com/GIS_in_Ecology_forum.htm<BR><BR>Books
>From GIS In Ecology Staff:<BR><BR>An Introduction To Using GIS In Marine
Biology; RRP: £44.99<BR>An Introduction To Using GIS In Marine Biology:
Supplementary Workbook One - Creating Maps Of Species Distribution; RRP: £19:99
<BR>An Introduction To Using GIS In Marine Biology: Supplementary Workbook Two -
Working With Raster Data Layers; RRP: £19.99 <BR><BR>If you wish to purchase
these books, visit: http://www.gisinecology.com/Book_Shop.htm<BR><BR>To help the
environment, please do not print out this email unless it is
unavoidable.<BR>==================================================================================</DIV></DIV></DIV></DIV></DIV></DIV>
<br /><br />
<hr style='border:none; color:#909090; background-color:#B0B0B0; height: 1px; width: 99%;' />
<table style='border-collapse:collapse;border:none;'>
<tr>
<td style='border:none;padding:0px 15px 0px 8px'>
<a href="http://www.avast.com/">
<img border=0 src="http://static.avast.com/emails/avast-mail-stamp.png" />
</a>
</td>
<td>
<p style='color:#3d4d5a; font-family:"Calibri","Verdana","Arial","Helvetica"; font-size:12pt;'>
This email is free from viruses and malware because <a href="http://www.avast.com/">avast! Antivirus</a> protection is active.
</p>
</td>
</tr>
</table>
<br />
</BODY></HTML>