[Qgis-user] averaging raster grid

M.E.Dodd m.e.dodd at open.ac.uk
Thu Apr 15 05:43:02 PDT 2010


http://www.amanita-photolibrary.co.uk/Untitled-2.png
humm, there does not seem to be any data there

-----Original Message-----
From: Micha Silver [mailto:micha at arava.co.il] 
Sent: 15 April 2010 12:05
To: M.E.Dodd
Cc: 'qgis-user at lists.osgeo.org'
Subject: Re: [Qgis-user] averaging raster grid

What I was hoping to see was something like this:
http://www.surfaces.co.il/wp-content/uploads/2010/04/GrassToolbox.png

Here we can determine how many features, what spatial extent.... Maybe 
that will give a hint why you're not seeing anything. Seeing this table 
for one of the rasters and the empty vector might be of help.

-- 
Micha

On 15/04/2010 12:57, M.E.Dodd wrote:
> http://www.amanita-photolibrary.co.uk/Untitled-1.jpg
>
> I've stuck a screenshot at the above location on my personal website, I will delete it eventually to stop things getting cluttered up, is there a more suitable place for these screenshots?
>
> Anyway, it shows the grass versions of the raster files, these are the ones that worked ok, also the vector shapefile just in qgis (all of these should be in same CRS).  Then it shows the dialogue box when I am trying to add the grass version of this shapefile that I had created earlier from the qgis version.  It is giving the error message 'no layers available in this map'.
> As I mentioned this is the first time I have tried this and I think I followed the manual correctly but have now got stuck.  I suspect its something quite straightforward that I am missing here but can't see what it is.
>
> -----Original Message-----
> From: Micha Silver [mailto:micha at arava.co.il]
> Sent: 14 April 2010 20:45
> To: M.E.Dodd; qgis-user
> Subject: Re: [Qgis-user] averaging raster grid
>
> M.E.Dodd wrote:
>
>    
>> Am still trying this.  Seems I might be nearly there but for some reason can't create a grass vector layer so can't use the v.rast.stats command.
>> I have created the grass raster layers from the raster layers that are open in qgis and they seem fine but when I try to create the grass vector layer it says its worked but then won't visualise it.  to summarise this part I have an open vector layer in qgis, also saved as a shapefile, when I run the command to convert this layer to a grass vector layer there are not errors but it won't visualise when the command completes and I can't add it as a new grass layer even though it says it recognises the filename.
>>
>>
>>      
> Hi Mike:
> (I'm assuming that the vector and raster are projected in the same CRS,
> and they overlap.)
> Can you open the GRASS toolbox and switch to the Browser tab. Then open
> the vector section, and click on this imported vector. On the right you
> should see a table similar to below.
> Please either post a screen shot on the web somewhere, or you can
> copy/paste the text into a mail message.  Send this to the qgis-user
> maillist and we can try to understand what is wrong.
> While you're at it, grab the same table of info for the raster, and post
> that as well...
>
> Vector
>
> 	
>
> veg
>
> Points
>
> 	
>
> 0
>
> Lines
>
> 	
>
> 0
>
> Boundaries
>
> 	
>
> 5732
>
> Centroids
>
> 	
>
> 835
>
> Areas
>
> 	
>
> 4293
>
> Islands
>
> 	
>
> 3516
>
> North
>
> 	
>
> 55:51:56.766357N
>
> South
>
> 	
>
> 39:35:35.604858N
>
> East
>
> 	
>
> 30E
>
> West
>
> 	
>
> 12:35:51.329041E
>
> 3D
>
> 	
>
> no
>
> History
> COMMAND: v.in.ogr -o
> dsn="/home/micha/geodata/Training/Geodata/vector/VMAP0/veg_cropland.shp"
> output="veg" min_area=0.0001 snap=-1
> GISDBASE: /home/micha/geodata/grass
> LOCATION: WGS84 MAPSET: PERMANENT USER: micha DATE: Wed Apr 14 22:21:18 2010
>
> ------------------------------------------------------------------------
>
> 802 input polygonsTotal area: 1.053955e+12 (4293 areas)Overlapping area:
> 7.020819e+09 (53 areas)Area without category: 1.341091e+11 (3458 areas)
>
>
>    


-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918


-- 
The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England & Wales and a charity registered in Scotland (SC 038302).




More information about the Qgis-user mailing list