[gdal-dev] Using GDAL with gridded XYZ that has no 'nodata' values?

[Even Rouault]

Le samedi 07 juin 2014 22:31:09, Sam Franklin a écrit :
> Hey Even - me again on this xyz sorting issue.
> 
> I've got a new xyz file that it is not recognised by gdal even after using
> the sort command you provided earlier in the thread.
> 
> The problem xyz is here |
> https://dl.dropboxusercontent.com/u/4086367/001-1.xyz.zip
> 
> The error is:
>  ERROR 1: Ungridded dataset: At line 363, X is 568509.090000, where as
> 568514.090000 was expected (1)
>  gdalinfo failed - unable to open '001-1.xyz'.
> 
> GDAL seems to fail at the start of a new row of data?
> 
> I've tried various descend/ascend combinations of the columns = no joy.
> 
> I'm running GDAL 1.11.0 on OSX 10.9.3.
> 
> Any ideas?  Thanks again in advance for any help! Very much appreciated.

The development version 2.0dev has improvements over 1.11 that would help a 
bit, but this file would still require additional developments since the 
spacing between horizontal or vertical coordinates isn't constant due to 
rounding to 2 decimal figures. Some tolerance should be added to the driver to 
support it.

> 
> Cheers
> Sam
> 
> 
> On 27 May 2014 14:09, Sam Franklin <mailinglist.samfranklin at gmail.com>
> 
> wrote:
> > Hi Even. Great, that worked for me too when sorting on both columns.
> > Really appreciate you help.
> > Sam
> > 
> > On 27 May 2014 01:31, Even Rouault <even.rouault at mines-paris.org> wrote:
> >> Le mardi 27 mai 2014 00:06:33, Sam Franklin a écrit :
> >> > Hey Even - great tip.  The sort command you suggested worked well with
> >> 
> >> that
> >> 
> >> > xyz dataset.
> >> > 
> >> > However, I've found a further dataset that does not work with gdal
> >> > even after the sort. This is the error:
> >> > 
> >> > mbp-sf:data08 samfranklin$ gdal_translate data08-02-sorted.xyz
> >> > data08-02.tif
> >> > Input file size is 4371, 11210
> >> > 0...10...20...30...40.ERROR 1: At line 1100207, found 48162.000000
> >> 
> >> instead
> >> 
> >> > of 48164.000000 for nBlockYOff = 4951ERROR 1: data08-02-sorted.xyz,
> >> 
> >> band 1:
> >> > IReadBlock failed at X offset 0, Y offset 4951
> >> > 
> >> > ERROR 1: GetBlockRef failed at X block offset 0, Y block offset 4951
> >> > 
> >> > See screenshot below, the data is arranged into three 'strips'. See
> >> 
> >> dropbox
> >> 
> >> > link to the data |
> >> > https://dl.dropboxusercontent.com/u/4086367/data08-02.xyz.zip
> >> > 
> >> > Any workaround you can think of?
> >> 
> >> Probably an issue with just sorting on column 2. I didn't have the same
> >> error
> >> as you, but anyway you should try :
> >> 
> >> sort -nk 2 -nk 1 data08-02.xyz > data08-02-sorted.xyz
> >> 
> >> with that I manage to translate the file.
> >> 
> >> --
> >> Geospatial professional services
> >> http://even.rouault.free.fr/services.html

-- 
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