similar to: repeat(?) measurement ANOVA or (general? mixed?) linear model?

I am trying to explore nlmer by running some nlme examples from Pinheiro & Bates (2000). I do not seem to find information how to specify fixed effects covariates to nlmer models. Specifically, I tried to run the "Carbon Dioxide Uptake" example from p. 368 onwards in the PB200 book. The model without fixed effects covariates runs well but how to tell nlmer to include Type and

Dear all, I did a non-linear least square model fit y ~ a * x^b (a) > nls(y ~ a * x^b, start=list(a=1,b=1)) to obtain the coefficients a & b. I did the same with the linearized formula, including a linear model log(y) ~ log(a) + b * log(x) (b) > nls(log10(y) ~ log10(a) + b*log10(x), start=list(a=1,b=1)) (c) > lm(log10(y) ~ log10(x)) I expected coefficient b to be identical

In postscript graphs (pointsize = 10, different sizes in graph adjusted via cex) I would like to use different font sizes but get the following warning message: Warning messages: 1: X11 used font size 8 when 9 was requested 2: X11 used font size 8 when 7 was requested 3: X11 used font size 8 when 5 was requested This is probably not a R but a X11 problem, nevertheless I would be most

Hello, I'm trying to adjust a non linear model in which the biological response variable (ratio of germinated fungus spores) is dependent on 2 covariates (temperature and time). The response to temperature is modeled by a kind of beta function with 2 parameters (optimal and maximum temperatures) and the time function is a 2-parameter Weibull. Adjustments with nls or gnls work, but I need to

Hi, I'm in dire need of a fast fourier transformation for me stupid biologist, i.e. I have a heartbeat signal and would like to decompose it into pure sin waves, getting three vectors, one containing the frequencies of the sin waves, one the magnitudes and one the phases (that's what I get from my data acquisition software's FFT function). I'd be very much obliged, if someone

We now have a draft of: Notes on the use of R for psychology experiments and questionnaires by Jonathan Baron and Yuelin Li at http://www.psych.upenn.edu/~baron/rpsych.htm and http://www.psych.upenn.edu/~baron/rpsych.pdf and http://www.psych.upenn.edu/~baron/rpsych.tex It is intended for students and others who are doing research in psychology. What makes it "for psychology" is that

Hi all, the following problem is still beyond my R-knowledge: I have one data vector containing the signal from 4 channels that are measured subsequently and in repeating cycles (with one factor vector for cycle and one for channel identification). To extract the mean of each channel during each cycle tapply is the method of choice. However, I cannot use the whole measuring period for each

Hi all -- So I'm working through my statistics homework again, and trying to reproduce the examples in the book (Kirk's _Experimental Design_, third edition) in R. This is a completely randomized hierarchical design (CRH-28(A)). The B factor is completely nested within the A factor. Pages 480-482, for those playing along at home. I can use: summary(aov(value ~ a + Error(b),

Hi there, I am quite new to R and I would like to ask two questions: * is it possible to cancel the memory of the arrow up command? * I am running a glm to model animal abundance relating it to research effort and other variables. I have 10 years of data and I am treating year as a factor, R is comparing each year with the first year my data sheet, while I would like to compare each

For those new to this list, I point out that Yuelin Li and I have drafted an introduction to R for psychology, trying to emphasize the things the psychologists usually do. It is at http://www.psych.upenn.edu/~baron/rpsych.pdf and http://www.psych.upenn.edu/~baron/rpsych.htm Because it is a draft, with frequent changes, we have not yet asked for it to be placed in the CRAN page. We welcome

Hi, I'm running a repeated measure ANOVA to test the effects of the within-subjects factors "congr", "isi" and their interaction, on the variable "latencies" aov(latencies ~ congr*isi + Error(subj/(congr*isi)),data=dats) "congr" has 4 levels, while "isi" has "3" levels. I would like to check for possible violations of the

Hi, I would like to run an ANOVA with repeated measures with both a between subjects variable and within subjects (repeated measures) variables. I know how to do this when I have equal numbers of subjects in both groups (i.e., balanced design). That has been very well documented by Baron, for example, see: http://cran.r-project.org/doc/contrib/Baron-rpsych.pdf On page 34 of this document,

Hi all, I've been reading about aov() at http://www.psych.upenn.edu/~baron/rpsych/rpsych.html and http://davidmlane.com/hyperstat/intro_ANOVA.html and I try to use this test in experiments with my simulator. What I would like Anova to tell me is whether the differences I see when plotting the means of performance per method are significant. And also, whether this is dependent on the problem

I have 2 questions on ANOVA with 1 between subjects factor and 2 within factors. 1. I am confused on how to do the analysis with aov because I have seen two examples on the web with different solutions. a) Jon Baron (http://www.psych.upenn.edu/~baron/rpsych/rpsych.html) does 6.8.5 Example 5: Stevens pp. 468 - 474 (one between, two within) between: gp within: drug, dose aov(effect ~ gp * drug *

dear List I have a dataset with blood measurements at 5 points in TIME (0,30,60,90,120) taken on 3 VISITS (same subjects). the interest is to compare these measurements between Visits, overall and at the different time points. I have problems setting up repeated measures ANOVA with 2 repeated measures (VISIT and TIME) (and then doing post hoc testing) or doing it with a linear mixed model ( both

Dear R Masters, I'm an anesthesiology resident trying to make his way through basic statistics. Recently I have been confronted with longitudinal data in a treatment vs. control analysis. My dataframe is in the form of: subj | group | baseline | time | outcome (long) or subj | group | baseline | time1 |...| time6 | (wide) The measured variable is a continuous one. The null hypothesis in

Hello all, thanks for your time and patience. I'm looking for a method in R to analyse the following data: Time to waking after anaesthetic for medical procedures repeated on the same individual. > str(mysurv) labelled [1:740, 1:2] 20 20 15 20 30+ 40+ 50 30 15 10 ... - attr(*, "dimnames")=List of 2 ..$ : NULL ..$ : chr [1:2] "time" "status" -

Dear Prof. Baron, thankyou for your pdf paper on using R, at http://www.psych.upenn.edu/~baron/rpsych.pdf I am currently interested in the sphericity notes on pp. 45-47. The equation on p. 46 suggests the following R calculation: D <- k^2 * ( mean(diag(S)) - mean(S) )^2 while the notes in the pdf indicate the following: D <- k^2 * ( mean(S) - mean(diag(S)) )^2 Can you please consider

With all the mess that my email has become, it makes sense for me to try to make use of Sieve, but I'm having quite the time finding out how to make it work. I'm running 1.0.13 on a Debian machine. Sieve appears to be compiled with it. I can access managesieve, and I have set up dovecot.conf with lda. I do not get a NO response when I PUTSCRIPI, but LISTSCRIPTS produces no result, so I

Hi, I have sort of a newbie question. I've seriously put a lot of effort into how to handle simple replicates in a repeated ANOVA design, but haven't had much luck. I really liked reading "Notes on the use of R for psychology experiments and questionnaires", by Jonathan Baron and Yuelin Li ( http://www.psych.upenn.edu/~baron/rpsych/rpsych.html ) but still didn't run across