[Spam/Pourriel] [GRASS-dev] Re: query vector points x,y

Patton, Eric epatton at nrcan.gc.ca
Wed Sep 27 09:26:19 EDT 2006


True enough. I'm not sure why v.to.db only prints a few decimal places. I'm
assuming there must be some print statement within one of the c programs of
v.to.db that determines this. 

~ Eric. 

-----Original Message-----
From: Damiano Triglione
To: Patton, Eric; 'Maciej Sieczka '
Cc: grass-dev at grass.itc.it
Sent: 9/27/2006 9:18 AM
Subject: Re: [Spam/Pourriel] [GRASS-dev] Re: query vector points x,y

You're perfectly right about practical meaning, but I have a theoretical

interest;
another issue is that for a strange reason I may want to use kilometers
as 
units, so meaningful centimeters are at distant decimal places!
What do you think?
Damiano

----- Original Message ----- 
From: "Patton, Eric" <epatton at nrcan.gc.ca>
To: "'Damiano Triglione '" <damiano.triglione at polimi.it>; "'Maciej
Sieczka 
'" <tutey at o2.pl>
Cc: <grass-dev at grass.itc.it>
Sent: Wednesday, September 27, 2006 2:50 PM
Subject: RE: [Spam/Pourriel] [GRASS-dev] Re: query vector points x,y


> I'm not sure why, but how much precision do you need? If your
projection
> units are in meters, you can't get meaningful precision greater than a
> decimeter anyway. Does it make sense to give coordinates for a
position to 
> 6
> decimal places if the units are meters? Is your input data that
precise?
> Keep in mind that 6 decimal places is giving a precision of 1/10,000th
of 
> a
> millimeter!
>
> ~ Eric.
>
> -----Original Message-----
> From: grass-dev-bounces at grass.itc.it
> To: Maciej Sieczka
> Cc: grass-dev at grass.itc.it
> Sent: 9/27/2006 8:16 AM
> Subject: [Spam/Pourriel] [GRASS-dev] Re: query vector points x,y
>
(...)
> OK, but then I think it is better to use v.out.ascii for this purpose!
> v.out.ascii print coordinates with high precision, while v.to.db -p
gives
> only
> a couple of decimals after floating  point. Why?
> Damiano
>
> _______________________________________________
> grass-dev mailing list
> grass-dev at grass.itc.it
> http://grass.itc.it/mailman/listinfo/grass-dev 




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