Re: st: Gen Randomized geo coordinates within a range

[Maarten Buis <maartenlbuis@gmail.com>]

On Fri, Aug 19, 2011 at 11:17 AM,  <graupel75@gmail.com> 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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