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

[Markus Metz]

On Mon, Apr 16, 2018 at 12:28 PM, Nikos Alexandris <nik at nikosalexandris.net>
wrote:
>
> * 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

This bbox is north of Ghana, not Ghana.

>
> # 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.

Apparently you did not update your local copy of trunk or relbr74, see my
previous post.

Markus M
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