[GRASS-user] sampling points in a grid

[Thomas Adams]

Margherita,

Actually, my approach with be little changed either way; without know of a
better GRASS-only approach, the kind of thing I have done is to:

(1) write-out to a text file for all grids x, y, value
(2) index the lines, producing, id, x, y, value
(3) in R randomly sample the index
(4) from (3) you have id, x, y, value for the random sample
(5) import (4) into grass using v.in.ascii

This will take a little scripting…

Best,
Tom


On Tue, Feb 17, 2015 at 8:49 AM, Margherita Di Leo <diregola at gmail.com>
wrote:

> Hi,
>
> I have a vector of points. According to a regular grid, I need to
> (randomly) sample a certain number n of these points in each cell of the
> grid. Such number n is given in a column of the attribute table of the
> grid. How would you do this?
> I have half idea to play with the coordinates and Monte Carlo, but I have
> the feeling that I'm not thinking GIS and there must be a easier way.
>
> Thank you for any hint
>
> --
> Best regards,
>
> Dr. Margherita DI LEO
> Scientific / technical project officer
>
> European Commission - DG JRC
> Institute for Environment and Sustainability (IES)
> Via Fermi, 2749
> I-21027 Ispra (VA) - Italy - TP 261
>
> Tel. +39 0332 78 3600
> margherita.di-leo at jrc.ec.europa.eu
>
> Disclaimer: The views expressed are purely those of the writer and may not
> in any circumstance be regarded as stating an official position of the
> European Commission.
>
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-- 
Thomas E Adams, III
718 McBurney Drive
Lebanon, OH 45036

1 (513) 739-9512 (cell)
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