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Re: st: Gen Randomized geo coordinates within a range
From
Maarten Buis <[email protected]>
To
[email protected]
Subject
Re: st: Gen Randomized geo coordinates within a range
Date
Fri, 19 Aug 2011 12:36:25 +0200
On Fri, Aug 19, 2011 at 11:17 AM, <[email protected]> wrote:
> I need to generate a set of random geographic coordinates (x,y) given
> a central point, within a given range.
Alternatively, if you want your range to be a circle with radius .5
you can do so as below
*-------------- begin example --------------
clear
input x y
1 1
5 5
1 5
end
forvalues i = 1/30 {
local phi = 2*runiform()*_pi
local r = .5*runiform()
gen xran`i' = `r'*cos(`phi') + x
gen yran`i' = `r'*sin(`phi') + y
local gr `"`gr' || scatter yran`i' xran`i'"'
}
scatter y x, aspect(1) `gr'
*-------------- end example -----------------
(For more on examples I sent to the Statalist see:
http://www.maartenbuis.nl/example_faq )
Hope this helps,
Maarten
--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://www.maartenbuis.nl
--------------------------
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