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From |
Jeph Herrin <junk@spandrel.net> |

To |
statalist@hsphsun2.harvard.edu |

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

Date |
Thu, 26 Feb 2009 16:33:30 -0500 |

Good idea. Austin Nichols wrote:

Jeph suggests the ceil() solution in a follow-up with the caveat "as long as uniform() never returns precisely 0, which I've never seen" --uniform() is 0 with probability about 1 in 4 billion, so to be safe you could gen y = x[ceil(_N*(1-uniform()))] On Thu, Feb 26, 2009 at 2:33 PM, Austin Nichols <austinnichols@gmail.com> wrote: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* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: random draw of single variable, not whole data***From:*Florian Wakolbinger <wakolbinger@drei-e.at>

**Re: st: random draw of single variable, not whole data***From:*Jeph Herrin <junk@spandrel.net>

**Re: st: random draw of single variable, not whole data***From:*Austin Nichols <austinnichols@gmail.com>

**Re: st: random draw of single variable, not whole data***From:*Austin Nichols <austinnichols@gmail.com>

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