[GRASS-dev] how to reproject a raster map with absolute numbers without losing data

[Moritz Lennert]

Le 30 novembre 2016 21:05:18 GMT+01:00, "Blumentrath, Stefan" <Stefan.Blumentrath at nina.no> a écrit :
>Hei,
>
>What about something like this (example converts from UTM33 to WGS84
>and creates ):
>r.stats -gn1 INPUTMAP | cs2cs -E -f "%.6f" +proj=utm +no_defs +zone=33
>+a=6378137 +rf=298.257222101 +towgs84=0.000,0.000,0.000 +to_meter=1 +to
>+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs | tr '\t' ' ' |
>r.in.xyz --o --v z=6 input=- output=REPROJECTED_MAP separator=space
>
>Or is cs2cs to slow 

I did a superficial test and it did seem quite slow. But I didn't try very hard.

>or does it modify also z?

AFAIK it modifies z. One would need to convert coordinates and then paste the new coordinates to the values.



>
>BTW, I think several modules would benefit from a -b do not build
>topology...


Which other modules are you thinking about?


Moritz