Re: [R] p values of lmer
On Jun 19, 2013, at 15:02 , R. Michael Weylandt wrote: On Wed, Jun 19, 2013 at 10:27 AM, meng laomen...@163.com wrote: Hi all: I met a question about lmer. fm1 - lmer(Reaction ~ Days + (Days|Subject), sleepstudy) summary(fm1) ... Fixed effects: Estimate Std. Error t value (Intercept) 251.405 6.825 36.84 Days 10.467 1.5466.77 ... My question: Why p values of (Intercept) and Days are not given? Take a look at R FAQ 7.35. http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-are-p_002dvalues-not-displayed-when-using-lmer_0028_0029_003f That's getting a bit old. It has a reference to Doug Bates posting from 2006, which basically says because degree of freedom issues are unresolved. Important developments have happened since, and Rune's reference to package lmerTest (and, implicitly, pbkrtest) is more precise these days. -- Peter Dalgaard, Professor Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd@cbs.dk Priv: pda...@gmail.com __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] p values of lmer
Try library(lmerTest) fm1 - lmer(Reaction ~ Days + (Days|Subject), sleepstudy) summary(fm1) Linear mixed model fit by REML Formula: Reaction ~ Days + (Days | Subject) Data: sleepstudy AIC BIC logLik deviance REMLdev 1756 1775 -871.8 17521744 Random effects: Groups NameVariance Std.Dev. Corr Subject (Intercept) 612.092 24.7405 Days 35.072 5.9221 0.066 Residual 654.941 25.5918 Number of obs: 180, groups: Subject, 18 Fixed effects: Estimate Std. Error t value Pr(|t|) (Intercept) 251.405 6.825 36.84 2e-16 *** Days 10.467 1.5466.77 3.27e-06 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Correlation of Fixed Effects: (Intr) Days -0.138 Cheers, Rune On 19 June 2013 11:27, meng laomen...@163.com wrote: Hi all: I met a question about lmer. fm1 - lmer(Reaction ~ Days + (Days|Subject), sleepstudy) summary(fm1) ... Fixed effects: Estimate Std. Error t value (Intercept) 251.405 6.825 36.84 Days 10.467 1.5466.77 ... My question: Why p values of (Intercept) and Days are not given? Many thanks! Best. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] p values of lmer
On Wed, Jun 19, 2013 at 10:27 AM, meng laomen...@163.com wrote: Hi all: I met a question about lmer. fm1 - lmer(Reaction ~ Days + (Days|Subject), sleepstudy) summary(fm1) ... Fixed effects: Estimate Std. Error t value (Intercept) 251.405 6.825 36.84 Days 10.467 1.5466.77 ... My question: Why p values of (Intercept) and Days are not given? Take a look at R FAQ 7.35. http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-are-p_002dvalues-not-displayed-when-using-lmer_0028_0029_003f Many thanks! Best. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] p values in lmer
This takes me back to listening to a professor lament about the researchers that would spend years collecting their data, then negate all that effort because they insist on using tools that are quick rather than correct. So, before dismissing the use of pvals.fnc you might ask how long it takes to run relative to how long it took to collect the data and the importance of the answer. If you feel the need to compute p-values multiple times, then you may need to rethink your approach (model selection based on repeated p-values results in p-values that are meaningless at best). If you consider the above and still feel the need for a quick p-value rather than a correct one then you can use the SnowsCorrectlySizedButOtherwiseUselessTestOfAnything function from the TeachingDemos package. It is quick (but be sure to fully read the documentation). -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of arunkumar Sent: Thursday, December 22, 2011 9:13 PM To: r-help@r-project.org Subject: [R] p values in lmer hi How to get p-values for lmer funtion other than pvals.fnc(), since it takes long time for execution - Thanks in Advance Arun -- View this message in context: http://r.789695.n4.nabble.com/p-values-in-lmer-tp4227434p4227434.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] p values in lmer
On Dec 22, 2011, at 11:13 PM, arunkumar wrote: hi How to get p-values for lmer funtion other than pvals.fnc(), since it takes long time for execution http://psy-ed.wikidot.com/glmm http://glmm.wikidot.com/faq -- David Winsemius, MD West Hartford, CT __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
