[gdal-dev] Opening gridded xyz data that is out of order

[Joaquim Luis]

You could have done it with GMT as well

gmtinfo DTM_swissALTI3D_XYZ.txt -I2
-R2708001/2717999/1210001/1219999

xyz2grd -R2708001/2717999/1210001/1219999 -I2 -GDTM_swissALTI3D_XYZ.grd  
DTM_swissALTI3D_XYZ.txt

and you get a netCDF grid (it can do GeoTIFs too but would need to go see  
the docs)

The grid misses a tile of data at the lower right corner

Joaquim

>
> Hi Mark (and others),
>
> Your sort command worked like a charm. It was also very fast!
>
> Now gdalinfo produces this nice information output:
>
> Driver: XYZ/ASCII Gridded XYZ
> Files: dtmav_sorted.xyz
> Size is 5000, 5000
> Coordinate System is `'
> Origin = (2708000.000000000000000,1210000.000000000000000)
> Pixel Size = (2.000000000000000,2.000000000000000)
> Corner Coordinates:
> Upper Left  ( 2708000.000, 1210000.000)Lower Left  ( 2708000.000,  
> 1220000.000)Upper Right ( 2718000.000, 1210000.000)Lower Right (  
> 2718000.000, 1220000.000)Center      ( 2713000.000, 1215000.000)Band 1  
> Block=5000x1 Type=Float32, ColorInterp=Undefined
>  Min=728.210 Max=2294.290 NoData Value=0
>
> Now I can open this in QGIS as a normal data source and simply safe as a  
> GeoTIFF file.
>
> Thanks a lot to all who answered so quickly!
>
> Glad that a simple sort command on the command line helped to solve the  
> issue! I will contact the data provider and ask them if they could  
> deliver this >data in an already sorted form so that GDAL recognizes it  
> as gridded data.
>
> Andreas
>
> On 11.09.2017 16:12, Mark Johnson wrote:
>> You must sort the data beforehand- the y position must be sorted  
>> properly (ASC or DESC)
>>
>> Standard linux sort program:
>>
>> sort -k2 -n -k1 392_5810.xyz -o 392_5810.sort.xyz
>>
>> (2nd column (y) as numeric, then first column (x) -o = output file
>>
>> As a zip file you can also do:
>>
>> unzip -p 390_5820.zip | sort -k2 -n -k1 -o ../xyz/390_5820.dhhn92.txt
>>
>> that would deal with problem in 1 step.
>>
>> ogr needs to know the range/area to build (minx,miny,maxx, maxy), so  
>> when the y switches it assumes a new column.
>>
>> Mark
>>
>>
>> _______________________________________________
>> gdal-dev mailing list
>> gdal-dev at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
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