The design is a repeated measures with 3 instances. There are 3 groups: Controls, Heavy Cocaine Users, Light Cocaine Users.
I reshaped the data so that there was one variable for the 3 instances called AvgTrials. Time is the indicator of each instance. Here is the model call: mod5 <- lme(AvgTrials ~ time + factor(group_id) + time*factor(group_id), random = ~ 1 | group_id, data = tmp.dat, method = "ML", na.action = na.omit) What else would you need here? -Edward On Mon, Sep 6, 2010 at 8:52 AM, ONKELINX, Thierry <thierry.onkel...@inbo.be>wrote: > Dear Edward, > > You have no degrees of freedom left to estimate those p-values. Your > design does not allows for the model your implemented. We need a brief > summary of your design in order to help you further. > > HTH, > > Thierry > > ------------------------------------------------------------------------ > ---- > ir. Thierry Onkelinx > Instituut voor natuur- en bosonderzoek > team Biometrie & Kwaliteitszorg > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > > Research Institute for Nature and Forest > team Biometrics & Quality Assurance > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > > tel. + 32 54/436 185 > thierry.onkel...@inbo.be > www.inbo.be > > To call in the statistician after the experiment is done may be no more > than asking him to perform a post-mortem examination: he may be able to > say what the experiment died of. > ~ Sir Ronald Aylmer Fisher > > The plural of anecdote is not data. > ~ Roger Brinner > > The combination of some data and an aching desire for an answer does not > ensure that a reasonable answer can be extracted from a given body of > data. > ~ John Tukey > > > > -----Oorspronkelijk bericht----- > > Van: r-help-boun...@r-project.org > > [mailto:r-help-boun...@r-project.org] Namens Edward Patzelt > > Verzonden: maandag 6 september 2010 15:43 > > Aan: r-help@r-project.org > > Onderwerp: [R] nlme Output > > > > Everyone - > > > > What do the NaN's mean here? Is this analysis a problem? > > > > > > Linear mixed-effects model fit by maximum likelihood > > Data: tmp.dat > > AIC BIC logLik > > 1611.251 1638.363 -797.6253 > > > > Random effects: > > Formula: ~1 | group_id > > (Intercept) Residual > > StdDev: 0.0003077668 9.236715 > > > > Fixed effects: AvgTrials ~ time + factor(group_id) + time * > > factor(group_id) > > Value Std.Error DF t-value p-value > > (Intercept) 18.159722 3.576664 213 5.077279 0.0000 > > time 4.192708 1.655674 213 2.532327 0.0121 > > factor(group_id)2 -6.929563 5.235700 0 -1.323522 NaN > > factor(group_id)3 -1.654554 4.189575 0 -0.394922 NaN > > time:factor(group_id)2 1.729911 2.423658 213 0.713760 0.4762 > > time:factor(group_id)3 -2.555111 1.939396 213 -1.317478 0.1891 > > Correlation: > > (Intr) time fc(_)2 fc(_)3 t:(_)2 > > time -0.926 > > factor(group_id)2 -0.683 0.632 > > factor(group_id)3 -0.854 0.790 0.583 > > time:factor(group_id)2 0.632 -0.683 -0.926 -0.540 > > time:factor(group_id)3 0.790 -0.854 -0.540 -0.926 0.583 > > > > Standardized Within-Group Residuals: > > Min Q1 Med Q3 Max > > -1.8842754 -0.6979785 -0.3370998 0.5666704 3.0943948 > > > > Number of Observations: 219 > > Number of Groups: 3 > > Warning message: > > In pt(q, df, lower.tail, log.p) : NaNs produced > > > > [[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. > > > > Druk dit bericht a.u.b. niet onnodig af. > Please do not print this message unnecessarily. > > Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver > weer > en binden het INBO onder geen enkel beding, zolang dit bericht niet > bevestigd is > door een geldig ondertekend document. The views expressed in this message > and any annex are purely those of the writer and may not be regarded as > stating > an official position of INBO, as long as the message is not confirmed by a > duly > signed document. > -- Edward H. Patzelt Research Assistant TRiCAM Lab University of Minnesota Psychology/Psychiatry VA Medical Center Office: N437 Elliot Hall - Twin Cities Campus Phone: 612-624-3892 Email: patze...@umn.edu Please consider the environment before printing this email www.psych.umn.edu/research/tricam [[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.
