[Qgis-user] averaging raster grid

[M.E.Dodd]

Came in this morning and was just about to post back to list saying how everything was fixed and working.  But then started up qgis, did a file, 'open recent project' to load up yesterday's work and the raster layers did not show, they were listed with a cross by them but nothing on screen even though they were showing fine yesterday.  Have just checked back at the screen dump from yesterday to check I am not completely loosing my mind and indeed they were there and the maps showing up (http://www.amanita-photolibrary.co.uk/Untitled-2).png).  The vector layer was fine.
So shut down qgis again and tried loading them one by one, they all loaded without a problem except they showed nothing on screen and the value tool suggests there is 'no data' when you move the mouse over where the map should be.  I've tried recreating the grass raster layers from the original raster layers in qgis and again the same problem, whereas all of this worked fine yesterday, indeed it still appears to work fine today:
"
r.in.gdal -o input=C:/Projects/cepaea_megalab/DEM/W020N40.DEM output=w020n40gn2



Over-riding projection check 






r.in.gdal complete. Raster map <w020n40gn2> created.

Successfully finished
"
But when you try to view output nothing appears.  Coordinate reference system is correct and there is a large file with this name that has been generated in the 'cell' part of where it should be.  I have checked the properties and its not set to transparent (I'm clutching at straws now), its at the top of the list so should be on top of anything else
http://www.amanita-photolibrary.co.uk/Untitled-3.png
the mouse is over NW Africa which is the w020n40gn2 area so it shows up the 'no data' in the value tool, the other raster layers are qgis ones (I have switched off the qgis version of w020n40)


-----Original Message-----
From: Micha Silver [mailto:micha at arava.co.il] 
Sent: 15 April 2010 19:02
To: M.E.Dodd
Subject: Re: [Qgis-user] averaging raster grid

M.E.Dodd wrote:
>
> I am running the v.in.ogr.qgis again and left it much longer even 
> after it said 100% and now notice that even after it gives 100% it 
> then goes onto other stages after a long wait so it appears that I may 
> not have been patient enough in the first place.  Perhaps a less 
> confusing progress indicator would be helpful as the bar has been 
> across to 100% several times now and the program is still running, no 
> idea how long it will actually take.  Ah now it says successfully 
> finished.
>
Good news.

GRASS always creates topologically correct vectors. That's an important 
feature for GIS, but a double edged sword since every import goes thru 
this long procedure of checking topology and fixing problems. That's 
probably what was happening.

Post back to the list how everything goes...

 

> Many thanks for all your help.  Will start the next stage and try to 
> be more patient!
>
> Mike
>
>  
>
> ------------------------------------------------------------------------


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