[GRASS-user] v.rast.stats

[Sandile Gumede]

Hi

It is still giving me -NULL value error.

Do you think maybe its the way I downloaded my rainfall data? This is the
site where I downloaded my data sets* ftp://trmmopen.gsfc.nasa.gov/pub/gis/
*and this data covers the whole world, the only thing I did was to clip a
specific region (using coordinates) that is in South Africa to do my
analysis. I used a bash script to download and project the data, see below:


#!/bin/bash

wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tif
wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tfw

gdal_translate -of GTiff -co "PROFILE=GeoTIFF" -co "INTERLEAVE=PIXEL" -co
"COMPRESS=LZW" -co "TILED=YES" -a_srs EPSG:4326 -a_ullr 18.2987501
-33.6795831 19.1712501 -34.3487498 3B42RT.2010032900.1day.tif
TRMMLast1day.tif




On Thu, Jun 17, 2010 at 8:41 AM, Sandile Gumede <akasandile at gmail.com>wrote:

> Hi
>
> It is still giving me -NULL value error.
>
> Do you think maybe its the way I downloaded my rainfall data? This is the
> site where I downloaded my data sets*
> ftp://trmmopen.gsfc.nasa.gov/pub/gis/ *and this data covers the whole
> world, the only thing I did was to clip a specific region (using
> coordinates) that is in South Africa to do my analysis. I used a bash script
> to download and project the data, see below:
>
>
> #!/bin/bash
>
> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tif
> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tfw
>
> gdal_translate -of GTiff -co "PROFILE=GeoTIFF" -co "INTERLEAVE=PIXEL" -co
> "COMPRESS=LZW" -co "TILED=YES" -a_srs EPSG:4326 -a_ullr 18.2987501
> -33.6795831 19.1712501 -34.3487498 3B42RT.2010032900.1day.tif
> TRMMLast1day.tif
>
>
>
> 2010/6/15 Micha Silver <micha at arava.co.il>
>
>>  On 15/06/2010 14:35, Sandile Gumede wrote:
>>
>> Hi
>> If I run g.region rast=rainfall -p, I get:
>>
>> OK, what you've done here is change the current region to match the raster
>> "rainfall".
>> Can you now try:
>> v.rast.stats -c vect=catchments rast=rainfall pref=precip
>>
>>
>>
>>
>> projection: 3 (Latitude-Longitude)
>> zone:       0
>> datum:      wgs84
>> ellipsoid:  wgs84
>> north:      33:40:46.49916S
>> south:      34:20:55.49928S
>> west:       18:17:55.50036E
>> east:       19:10:16.50036E
>> nsres:      0:00:05.01875
>> ewres:      0:00:02.18125
>> rows:       480
>> cols:       1440
>> cells:      691200
>>
>> and If I run r.univar rainfall, I get the following output:
>>
>>  100%
>> total null and non-null cells: 691200
>> total null cells: 0
>>
>> Of the non-null cells:
>> ----------------------
>> n: 691200
>> minimum: 0
>> maximum: 3094
>> range: 3094
>> mean: 22.0228
>> mean of absolute values: 22.0228
>> standard deviation: 76.1639
>> variance: 5800.94
>> variation coefficient: 345.841 %
>> sum: 15222164
>>
>>
>>
>> On Tue, Jun 15, 2010 at 12:22 PM, Hamish <hamish_b at yahoo.com> wrote:
>>
>>> Micha wrote:
>>> > The only unusual thing I notice above is that the resolution settings
>>> > for the raster are different N-S and E-W. This came from the original
>>> > tiff (see below) which also has rectangular pixels,
>>>
>>>  that is perfectly normal for a lat/lon map away from the equator.
>>> longitude scales a cos(lat).
>>>
>>>
>>> > (the v.rast.stats module creates a temp raster at the *current region's
>>> > resolution* settings, which might be different from this rainfall
>>> > raster's rectangular resolution...)
>>>
>>>  the results of:
>>>
>>> g.region -p rast=mapname
>>> r.univar mapname
>>>
>>>
>>> could help.
>>>
>>>
>>> Hamish
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Kind Regards
>> TS Gumede
>> CSIR, Meraka Institute
>> 072 258 1650
>>
>>
>> This mail was received via Mail-SeCure System.
>>
>>
>>
>> --
>> Micha Silverhttp://www.surfaces.co.il/
>> Arava Development Co.  +972-52-3665918
>>
>>
>
>
> --
> Kind Regards
> TS Gumede
> CSIR, Meraka Institute
> 072 258 1650
>
>


-- 
Kind Regards
TS Gumede
CSIR, Meraka Institute
072 258 1650
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/grass-user/attachments/20100617/75f2abc7/attachment.html