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Generating random geographical coordinates

3 messages · Poizot Emmanuel, R. Michael Weylandt, Berend Hasselman

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Dear all,

I have two coordinates vectors, say X and Y of length n.
I want to generate for each couple of coordinates X1,Y1 X2,Y2 
X3,Y3....Xn,Yn a random coordinate which is located in a square define 
as X +/- dx and Y +/- dy.
I saw the runif function which can generate for just one value at a time 
what I want  : runif(1, X - dx, X + dx) for X and runif(1, Y - dy, Y + 
dy) for Y.
I would like to know if there is not a more powerfull way in R to 
generate directly the set of random coordinates.
Regards
#
Change 1 to some other number to get more points from runif()

More generally, take a look at "An Introduction to R" and read most
everything you can find on the topic of vectorization. If you don't
know how to get "An Introduction to R", try typing help.start() at
your prompt and it should happen automatically.

Cheers,
Michael

On Wed, Oct 10, 2012 at 3:15 PM, Poizot Emmanuel
<emmanuel.poizot at cnam.fr> wrote:
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On 10-10-2012, at 16:15, Poizot Emmanuel <emmanuel.poizot at cnam.fr> wrote:

            
Yes there is. Just do

?runif

to get help on runif.

Berend