[GRASS5] [bug #3886] (grass) upload loop error in v.distance

[Michael Barton]

You've set the -a flag, which asks v.distance to computer the distance from
a point to ALL points in the file. The 0 values represent the distance from
a point to itself. 

This is pretty easy to get rid of in any kind of dbms or stat program--or
even with shell scripting commands. However, it is also helpful marking when
distances to a new point is being measured. To see an example of how this
can be used, look at the v.lda script I did (on the WIKI) to compute local
density analysis scores.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton



> From: Request Tracker <grass-bugs at intevation.de>
> Reply-To: Request Tracker <grass-bugs at intevation.de>
> Date: Wed,  7 Dec 2005 15:37:11 +0100 (CET)
> To: <grass5 at grass.itc.it>
> Subject: [GRASS5] [bug #3886] (grass) upload loop error in v.distance
> 
> this bug's URL: http://intevation.de/rt/webrt?serial_num=3886
> -------------------------------------------------------------------------
> 
> Subject: upload loop error in v.distance
> 
> Platform: Mac OSX
> grass obtained from: Other (CDROM etc)
> grass binary for platform: Downloaded precompiled Binaries
> GRASS Version: 6.1cvs (Moretti)
> 
> When running:
> 
> v.distance -a kenpoints to=kenbnd table=bdist column=distance upload=dist
> 
> the output dbf reads as follows:
> 
> from_cat   distance
> 5              0
> 5              342
> 5              284
> 2              156
> 2              0
> 2              301
> 8              12
> 8              19
> 8              0
> 4              956
> ...and so on
> 
> Notice how a zero value is written in the index position of the given object -
> i.e. first for the first
> point listed, second for the second, etc. This causes problems when doing
> various statistical
> manipulations with the data. A fix would be a big help!
> 
> -------------------------------------------- Managed by Request Tracker
>