[R] the problem about sample size
petr.pikal at precheza.cz
Mon Mar 5 08:21:25 CET 2012
I am not at all an expert in this matter, so you shall copy you message to
r-help list too. However I would try na.action=na.exclude as it shall
preserve the length of variables.
> Sorry I didn't know the original post in this thread was not included.
> using R version 2.14.0 (2011-10-31).
> This is the program:
> fitLME4 <- lme(iadl ~ obstime,
> random = ~ obstime | id, data = iadl.long.df, na.action=na.omit)
> fitSURV <- coxph(Surv(Time, death) ~ agew1, data = last_aa.df, x = TRUE)
> fit.JM4 <- jointModel(fitLME1, fitSURV, timeVar = "obstime", method =
> This is the error message:
> Error in jointModel(fitLME1, fitSURV, timeVar = "obstime", method =
> "piecewise-PH-GH") :
> sample sizes in the longitudinal and event processes differ; maybe you
> forgot the cluster() argument.
> I have missing data in the lme data and that's why I used na.omit. But
> results of the lme and coxph show the same number of participants.
> From lme:
> Number of Observations: 4818
> Number of Groups: 2087
> From coxph:
> n= 2087, number of events= 1721
> If the number of groups in lme = n in coxph, why am I getting the error
> message that sample sizes differ?
> Many thanks for your help.
> From: Petr PIKAL [petr.pikal at precheza.cz]
> Sent: Thursday, March 01, 2012 6:17 PM
> To: Helena Chui
> Cc: r-help at r-project.org; r-help-bounces at r-project.org
> Subject: Re: [R] the problem about sample size
> > Hi, there,
> > I run into the same sample size error in JM. Have you found the
> > the error?
> What error?
> > Many thanks,
> > Helena
> > --
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> > about-sample-size-tp1592855p4434009.html
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