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From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Collecting Statistics of Averages of Variables |

Date |
Sat, 29 Sep 2012 02:40:47 +0100 |

-statsby- can help there too. Do look at the -subsets- option. Nick On Fri, Sep 28, 2012 at 9:53 PM, robert hartman <rohartman@gmail.com> wrote: > Thanks, Nick. This looks helpful. Where I'm still a bit hung up is the > coding (I assume some kind of loop) to put together all the > combinations, including combinations of varying sizes (e.g., > 3-variable and 2-variable combinations). > > I assume there's a fairly straightforward way to do this w/ loops, but > it's not jumping out at me. > > Thanks, > Rob > > (BTW, failed to mention, I'm on Stata 11.2) > > On Fri, Sep 28, 2012 at 2:24 PM, Nick Cox <njcoxstata@gmail.com> wrote: >> Check out -statsby-. >> >> Nick >> >> On 28 Sep 2012, at 18:55, robert hartman <rohartman@gmail.com> wrote: >> >>> Hi Listers, >>> I'm struggling with a couple of programming challenges. I will start >>> with this one. Any input on efficient ways to code this would be most >>> appreciated. >>> >>> I want to take mean (or could be other "egen"/"collapse" type summary >>> statistic) form all possible combinations (of subsets of various >>> sizes) from a set of variables. >>> >>> For example, if I have v1, v2, v3, and v4, I would want the mean of >>> each: v1v2, v1v3, v1v4, v1v2v3, v1v2v4, v1v3v4...v3v2...v3v2v4, etc. >>> >>> By v1v2v3, I mean gen v1v2v3=(v1+v2+v3)/3; (assuming the summary >>> statistic of interest is the mean) >>> by v1v2v3v4, I mean v1v2v3v4=,I mean gen v1v2v3v4=(v1+v2+v3+v4)/4. >>> >>> etc. >>> >>> I don't need to actually create permanent variables, simply >>> 1. create a temporary "combination variable" (e.g., v1v2v4 = >>> rowmean(v1 v2 v4)) for each possible combination, >>> 2. collect summary statistics of interest from "combination variables." >>> 3. spit out a file that conveys this information intelligibly >>> >>> For example, I may want to write out a file that gives (a) the name of >>> the combination (e.g., v1v2v4--the column representing the rowmean of >>> those three variables) and (b) the mean and standard deviation of that >>> v1v2v4 variable. >>> >>> In my particular case, I have about a 70 variable space from which to >>> create all these subset combinations. >>> >>> Any helpful starting points or coding ideas would be helpful. >>> >>> Thanks, >>> Rob Hartman >>> * >>> * For searches and help try: >>> * http://www.stata.com/help.cgi?search >>> * http://www.stata.com/support/faqs/resources/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/faqs/resources/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/faqs/resources/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/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**References**:**st: Collecting Statistics of Averages of Variables***From:*robert hartman <rohartman@gmail.com>

**Re: st: Collecting Statistics of Averages of Variables***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Collecting Statistics of Averages of Variables***From:*robert hartman <rohartman@gmail.com>

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