[gdal-dev] gdal_grid help

[Jeff Lake]

Evan ...
Thanks .. still seeing a basically blank tiff, but decided to press on
to the next step creating a contour shapefile from said raster ..
and that works !!
as long as that is my end result... Im happy

-Jeff Lake
MichiganWxSystem.com
AllisonHouse.com
TheWeatherCenter.net
GRLevelXStuff.com

On 9/23/2012 3:54, Even Rouault wrote:
> Le dimanche 23 septembre 2012 06:20:27, Jeff Lake a écrit :
>> ugh..
>> I have been attempting to create an interpolated (IDW) raster from CSV,
>> to no avail all I get is either a totally black tiff or white tiff
>> here is the command line I have been trying
>>
>> gdal_grid -a invdist:power=2.0:smoothing=1.0 -outsize 800 600 -ot
>> Float64 -l temps temps.vrt temps.tiff
>>
>> and the CSV http://metar.michiganwxsystem.net/temps.csv
>>
>> here is the vrt
>>
>> <OGRVRTDataSource>
>>       <OGRVRTLayer name="temps">
>> <SrcDataSource>/var/www/html/metar/temps.csv</SrcDataSource>
>>           <GeometryType>wkbPoint</GeometryType>
>> <GeometryField encoding="PointFromColumns" x="Longitude" y="Latitude"/>
>>    <LayerSRS>WGS84</LayerSRS>
>>       </OGRVRTLayer>
>> </OGRVRTDataSource>
>>
>>
>> anybody gather where I'm going wrong ??
> Jeff,
>
> The issue here is that gdal_grid doesn't find the value to interpolate from.
>
> 2 possibilities :
>
> - change the <GeometryField> element as the following so that the value of the
> temps field is set as the Z value of the geometry :
> <GeometryField encoding="PointFromColumns" x="Longitude" y="Latitude"
> z="temps"/>
>
> - or specify "-zfield temps" on the gdal_grid command line
>
> Best regards,
>
> Even
>
>