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

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Mean calculation under consideration of different dates |

Date |
Wed, 12 Jan 2011 13:39:22 +0000 |

This is discussed explicitly in the Tip earlier cited with code examples. As you say, you need to add a condition of the form id == id[`i'] to the -if- condition. Here -id- is an example identifier which tells you what group you are in. Your variable name may well be different. Using more words, you are insisting that identifier == identifier of this observation or that the observations used must be in the same group. Nick On Wed, Jan 12, 2011 at 1:24 PM, <shausen@smail.uni-koeln.de> wrote: > first many thanks to Nick for sending me the Stata Journal Tip. Nevertheless > I still got some problems with telling Stata to calculate the mean for the > whole dataset but apply the loop for different groups defined by two > variables (company ticker and a date). Based on the tip I tried: > > gen meanb= . > quietly forval i=1`/=_N'{ > summarize forecast if inrange (estdats[`i']-estdats,1,90), meanonly > replace meanb= r(mean) in `i' > } > > How can I tell Stata to differ between certain groups? Using bysort before > the loop does not work but I guess I should include some "sort-command" > within the loop anyway. Maybe a tag() or id=id[`i']? Any advice is > appreciated. > > > > Zitat von Nick Cox <njcoxstata@gmail.com>: > >> Check out >> >> SJ-7-3 pr0033 . . . . . . . . . . . . . . Stata tip 51: Events in >> intervals >> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. >> Cox >> Q3/07 SJ 7(3):440--443 (no >> commands) >> tip for counting or summarizing irregularly spaced >> events in intervals >> >> <http://www.stata-journal.com/sjpdf.html?articlenum=pr0033> >> >> On Thu, Jan 6, 2011 at 6:43 PM, <shausen@smail.uni-koeln.de> wrote: >> >>> I've got a large dataset that includes forecasts of growth rates for >>> different periods reported by different analysts at different dates. I >>> already sorted the data to make sure that the analysts forecasts refer to >>> the same firm and the same date. >>> In anext step the mean of the analysts growth rate forecasts should be >>> calculated under the assumption that only those forecasts should be taken >>> into account that were issued maximum 90 days prior to the forecast of a >>> certain analyst. >>> analyst est date forecast mean >>> 11 15.Feb 2010 0,3 0,225 >>> 22 08.Jan 2010 0,2 0,3 >>> 33 01.Jan 2010 0,25 >>> 44 01.Nov 2009 0,35 >>> >>> The mean calculation for analyst 11 for example consists of the forecasts >>> of >>> analyst 22 and analyst 33 to be in line with the maximum 90 days >>> assumption. >>> In addition the analysts own forecast should not be considered when >>> calculating the mean but I guess Stata does it automatically. >>> Any hints or tips are warmly welcomed. * * 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/

**Follow-Ups**:**Re: st: Mean calculation under consideration of different dates***From:*shausen@smail.uni-koeln.de

**References**:**st: Mean calculation under consideration of different dates***From:*shausen@smail.uni-koeln.de

**Re: st: Mean calculation under consideration of different dates***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Mean calculation under consideration of different dates***From:*shausen@smail.uni-koeln.de

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