[GRASS-dev] r.in.gdal -r and r.import extent=region not working properly?

[Nikos Alexandris]

* Markus Neteler <neteler at osgeo.org> [2018-04-15 22:49:09 +0200]:

>On Sun, Apr 15, 2018 at 9:46 PM, Markus Neteler <neteler at osgeo.org> wrote:
>> On Sun, Apr 15, 2018 at 8:48 PM, Veronica Andreo <veroandreo at gmail.com> wrote:
>>> Hi devs,
>>>
>>> I just found something odd. I have a CHIRPS tif for Africa [0], but I would
>>> only need to import Ghana, so I used r.in.gdal -r. However when I visualize
>>> the data, most of it is nodata, while the full map of Africa has data all
>>> over the continent. Then, I tried also with r.import extent=region. Same
>>> result. The only thing providing what I expected to be the right result (a
>>> subset from the full map) is importing the whole map and then using
>>> r.mapcalc to clip (i need the space in my hard disk)
>
>trying harder I can reproduce the issue (of course not NULL related).
>
>So, I have no clue right now why it behaves differently.

Hi,

no intention to add noise. There is something weird, here too.

# first things first
grass -c /geo/geodata/examples/chirps-v2.0.2018.01.01.tif /geo/grassdb/onsight/chirps

# importing the whole map looks visually ok
r.in.gdal input=/geo/geodata/examples/chirps-v2.0.2018.01.01.tif output=chirps_v2

# then, using the following box coordinates for Ghana from
# https://en.wikipedia.org/wiki/User%3aThe_Anome/country_bounding_boxes
g.region w=-4.000 e=4.733 n=20.000 s=11.167 -p

# to draw the box on-display
v.in.region output=ghana_box

# and doing a partial import
r.in.gdal -r input=/geo/geodata/examples/chirps-v2.0.2018.01.01.tif output=chirps_v2_subset

Regardless whether the box figures are not correct, while the imported
portion is, indeed, a box fraction of the whole map, it isn't, visually
the "right" part. It appears as a part from the coast has been imported.

I am double-checking the steps I followed, I always get the same.

?

Nikos
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