[GRASS5] floating AI ASCII GRID import

Maciek Sieczka werchowyna at pf.pl
Sat Nov 27 15:51:55 EST 2004

From: "Frank Warmerdam" <fwarmerdam at gmail.com>

>> The value range should be:
>> min=176.945400
>> max=284.015600
>> And it is the case when 'r.in.arc type=DCELL' is used for importing.
>> However, if 'r.in.gdal' or 'r.in.arc type=FCELL' is used then:
>> min=176.945404
>> max=284.015594
>> I suppose there should be no difference. What is the reason?

> Well, the obvious conclusion is that a FCELL, which I presume reads as a
> 4byte float gives
> slightly less precision than DCELL which is an 8byte float.  The change
> in the seventh digit would  seem to be what we would expect from floating 
> point precision limitations.

Ok, so why doesn't r.in.gdal recognize what precission the input requires? 
Actually, all floating point AI ASCII GRIDs I met were DCELL, no matter 
where they came from. So maybe the default for the r.in.gdal in case of the 
AI ASCII GRID should be DCELL instead of FCELL?

GRASS DEVELOPERS - I couldn't find a GUI entry for the 'r.in.arc' in the 
File->Import->Raster. Shouldn't it be there?


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