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From |
"Nick Cox" <n.j.cox@durham.ac.uk> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: generate new variable with frequencies |

Date |
Tue, 4 Nov 2003 12:56:22 -0000 |

The frequencies of -type- can be put in -typ_freq- by bysort type : gen typ_freq = _N If you want to scale to relative frequencies (sum 1) then you can su typ_freq, meanonly replace typ_freq = typ_freq / r(sum) and percents naturally can be obtained with a factor of 100. Some care will often be needed over missing values: bysort type : gen typ_freq = _N if !missing(type) su typ_freq, meanonly replace typ_freq = typ_freq / r(sum) Another way to do it: egen typ_freq = sum(1) if !missing(type), by(type) Nick n.j.cox@durham.ac.uk Matteo Foschi > > We have a little trouble with a, we think, easy task. > We want to generate a variable, which contains the relative > frequency of > another variable values. > We have a variable, say “type”, and want to built a new variable, > say “typ_freq”, which shows the relatively frequency of > each value of “type”. > > We have tried first with the tablepc ado-file: > tablepc type, generate (typ_freq) > Therefore we obtain only the relatively frequency of each > observation. > > We can obtain - in alternatively - the cumulated frequency > (variable freqcum) > with a little program: > > Generate freqcum =. > .. > sort typ_freq > by typ_freq: gen groups = 1 if _n ==1 > replace groups = sum(groups) > .. > local K = groups[_N] > local i 1 > while `i' <= `K' { > replace freqcum = sum(typ_freq) > local i = `i' + 1 > } > .. > We are not able, however, to recode freq_cum or typ_freq > in order to obtain > the relatively frequency of each value of “type”, as bottom shows: > > Obs Type obs_freq freq_cum typ_freq > 1 1 1 1 2 > 2 1 1 2 2 > 3 2 1 3 3 > 4 2 1 4 3 > 5 2 1 5 3 > 6 3 1 6 1 > 7 4 1 7 2 > 8 4 1 8 2 > 9 5 1 9 1 > 10 6 1 10 1 > * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**st: RE: RE: generate new variable with frequencies***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**References**:**st: generate new variable with frequencies***From:*Matteo Foschi <foschi@rumms.uni-mannheim.de>

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