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Re: st: random draw of single variable, not whole data


From   Austin Nichols <austinnichols@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: random draw of single variable, not whole data
Date   Thu, 26 Feb 2009 14:33:35 -0500

With replacement:
  gen y = x[round(_N*uniform(),1)+1]

should be
  gen y = x[round(_N*uniform()+.5)]
or
  gen y = x[ceil(_N*uniform())]

I think.... (otherwise you can get _N+1 in the square brackets, for a
missing y, and the prob of getting y[1] is too low)

On Thu, Feb 26, 2009 at 2:19 PM, Jeph Herrin <junk@spandrel.net> wrote:
>
> It's not clear if you want sampling with or without replacement.
>
> With replacement:
>
>  gen y = x[round(_N*uniform(),1)+1]
>
> without replacement:
>
>  egen index=rank(uniform())
>  gen y = x[index]
>
> hth,
> Jeph

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