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Managing person identifier variable

Theodore Lytras · 2016-10-05T19:21:38Z

???? ???????, 5 ????????? 2016 6:59:30 ?.?. EEST MACDOUGALL Margaret ??????: > I would be most grateful for some advice in relation to the interpretation > of a person identifier variable (persID, say), in R. I would like to > represent persons, as an independent variable, by a random effect. However, > there are over 200 such persons. Each person is allocated a random > numerical code as a unique identifier. Currently, R is reading the > identifier variable as a numeric variable. Is there a q

Theodore Lytras

Wed, Oct 5, 2016 12:21 PM

???? ???????, 5 ????????? 2016 6:59:30 ?.?. EEST MACDOUGALL Margaret ??????:

Just recode it as a factor, i.e. factor(persID).

By the way, lme4 does that implicitly if you specify a numeric variable as a 
random effect in a model formula, i.e. you can just say: y ~ x + (1|persID) 
instead of: y ~ x + (1|factor(persID))

Thread (4 messages)

MACDOUGALL Margaret Managing person identifier variable Oct 5 Marc Schwartz Managing person identifier variable Oct 5 Theodore Lytras Managing person identifier variable Oct 5 Marc Schwartz Managing person identifier variable Oct 5