[gdal-dev] python code inside of VRT results to empty values

[Jachym Cepicky]

Aahaa, the problem was

out_ar[:] = data

while I was using

out_ara = data

Thank you!

Jachym

po 25. 5. 2020 v 11:14 odesílatel Even Rouault
<even.rouault at spatialys.com> napsal:
>
> On lundi 25 mai 2020 10:44:10 CEST Jachym Cepicky wrote:
>
> > Hi all,
>
> >
>
> > I have some python code inside of VRT file, but I can not produce
>
> > reasonable output with gdal_transalte. All the input data do look ok,
>
> > even when I print() the values I would like to store, the data are
>
> > displayed, but the resulting TIFF file is just empty, any hint how to
>
> > approach? I've tested it on gdal 2.2 as well as 3.8, so I assume, I do
>
> > something wrong here. The minimal code looks like
>
> >
>
> > import numpy as np
>
> > import copy
>
> > def blur(in_ar, out_ar, xoff, yoff, xsize, ysize, raster_xsize,
>
> > raster_ysize, buf_radius, gt, **kwargs):
>
> > out_ar = copy.copy(in_ar[0])
>
> > print(out_ar)
>
> > return out_ar
>
> >
>
> > Any hint?
>
>
>
> Actually, just realizing that you just don't follow the expectations of the
>
> pixel function. The function should not return an array: it must modify in place
>
> the provided out_ar argument.
>
> Like all examples at
>
> https://gdal.org/drivers/raster/vrt.html#using-derived-bands-with-pixel-functions-in-python
>
>
>
> Even
>
>
>
> --
>
> Spatialys - Geospatial professional services
>
> http://www.spatialys.com



-- 
Jachym Cepicky
e-mail: jachym.cepicky gmail com
URL: http://les-ejk.cz
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