similar to: lme() with two random effects

Hi all, I understand that it is simple to create data with a specific correlation (say, .5) using mvrnorm from the MASS library: > library(MASS) > set.seed(1) > > a=mvrnorm( + n=10 + ,mu=rep(0,2) + ,Sigma=matrix(c(1,.5,.5,1),2,2) + ,empirical=T + ) > a [,1] [,2] [1,] -1.0008380 -1.233467875 [2,] -0.1588633 -0.003410001 [3,] 1.2054727 -0.620558768

Hi all, Hopefully this will be quick, I'm looking for pointers to packages/ functions that would allow me to calculate the power of a t.test when the DV has measurement error. That is, I understand that, ceteris paribus, experiments using measure with more error (lower reliability) will have lower power. Mike -- Mike Lawrence Graduate Student, Department of Psychology, Dalhousie

Hi all, A suggestion derived from discussions amongst a number of R users in my research group: set the default column names produced by aggregate () equal to the names of the objects in the list passed to the 'by' object. ex. it is annoying to type with( my.data ,aggregate( my.dv ,list( one.iv = one.iv ,another.iv = another.iv ,yet.another.iv = yet.another.iv )

Hi all, This is my first post to the developers list. As I understand it, aggregate() currently repeats a function across cells in a dataframe but is only able to handle functions with single value returns. Aggregate() also lacks the ability to retain the names given to the returned value. I've created an agg() function (pasted below) that is apparently backwards compatible (i.e.

Hi I''d like to create a webcal link to share a calendar with iCal like it''s done in Basecamp for example. I know how to create the file using icalendar ruby library and iCal can open it, but if I send this file using an url like webcal:// localhost:3000/ical/1151495837 iCal says that data are not valid. Any ideas? Thanks. PS here is my rb code def ical_data cal

Hi all, Just thought I'd share something I discovered last night. I was interested in creating animations consisting of a series of plots and after finding very little in the usual sources regarding animation in R directly, and disliking the imagemagick method described here (http://tolstoy.newcastle.edu.au/R/help/05/10/13297.html), I discovered that if one exports the plots to a

Hi all, Consider the following function: #### my.func = function(x){ y=ifelse(x>-.5,0,ifelse(x< -.8,abs(x)/2,abs(x))) print(c(x,y)) #print what was tested and what the result is return(y) } curve(my.func,from=-1,1) #### When I attempt to find the maximum of this function, which should be -.8, I find that optimize gets stuck in the plateau area and doesn't bother testing the

You could calculate the confidence interval of the correlation at your desired df: http://davidmlane.com/hyperstat/B8544.html The below code takes as arguments the observed correlation, N, and alpha, calculates the confidence interval and checks whether this includes 0. cor.test2=function(r,n,a=.05){ phi=function(x){ log((1+x)/(1-x))/2 } inv.phi=function(x){

Hi all, Tinkering with a wrapper for xyplot that will help me plot a bunch of plots in a data analysis I'm doing and I ran into an odd error that I'm guessing is a scope issue. Here's a very simple version of the code: ############### #load lattice library(lattice) #create the wrapper function do.xyplot = function( plot.formula, data.frame, plot.groups){ print(plot.groups)

Hi all, Looking to calculate the expected mean and variance of a ratio distribution where the source distributions are gaussian with known parameters and sample values are correlated. I see (from wikipedia: http://en.wikipedia.org/wiki/ Ratio_distribution#Gaussian_ratio_distribution) that this calculation is quite involved, so I'm hoping that someone has already coded a function to

Hi all, I'm using the code below within a loop that I run thousands of times and even with the super-computing resources at my disposal this is just too slow. The snippet below takes about 10s on my machines, which is an order of magnitude or two slower than would be preferable; in the end I'd like to set the number of monte carlo experiments to 1e4 or even 1e5 to ensure stable

We''re using Vpim to parse iCal and vCard files, and so far it''s been great. However, when we were parsing some iCal files we noticed that all the endlines in the description section were disappearing. I start peering through the source code and find (in the Field#to_text method that is being called): # The value as text. Text can have escaped newlines, commas, and escape #

I am running Samba Version 3.0.23a on a Solaris 10 machine. On Windows XP I can map a drive to \\www\webcal I can't do this on a WIndows 2003 machine. I get an error message stating "The drive couldn't be mapped because no network was found" I have not been able to find a solution for this. Larry

Dear R people, I am having a problem with modeling the following SAS code in R: Class ID Gr Hemi Region Gender Model Y = Gr Region Hemi Gender Gr*Hemi Gr*Region Hemi*Region Gender*Region Gender*Hemi Gr*Hemi*Region Gender*Hemi*Region Gr*Gender*Hemi*Region Random Intercept Region Hemi /Subject = ID (Gr Gender) I.e., ID is a random effect nested in Gr and Gender, leading to ID-specific

Hi everyone, I'm having some difficulty getting "simple effects" for the ols() function in the rms package. The example below illustrates my difficulty -- I'll be grateful for any help. #make up some data exD <- structure(list(Gender = structure(c(1L, 2L, 1L, 2L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 2L), .Label = c("F", "M"), class = "factor"),

This isn''t even close to ready for release, but in case anybody is interested, has feedback, finds it useful as is, or even wants to collaborate... I''ve been working on a "personal information server", something of a protocol multiplexer. Right now it serves calendar feeds for: - a local calendar folder (iCal 1.x''s Library/Calendars) - rss for local todos

How do we specify a contrast interaction matrix for an ANOVA model? We have a two-factor, repeated measures design, with Cue Direction (2) x Brain Hemisphere(2) Each of these has 2 levels, 'left' and 'right', so it's a simple 2x2 design matrix. We have 8 subjects in each cell (a balanced design) and we want to specify the interaction contrast so that: CueLeft>CueRght

Hi, I have some general questions about statistical analysis for a research dataset and a request for advice on using R and associated packages for a valid analysis of this data. I can only pose the problem as how to run multiple ANOVA tests on time series data, with reasonable controls of the family-wise error rate. If we run analysis at many small sections of a long time-series, the Type-I

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I'm trying to use flac to make backups of my CD collection, and am running into problems with disks that contain a pregap (or lead-in) before the start of track one. cdrdao rips these disks *WITHOUT* the pregap, and puts a PREGAP entry into the cue file. For my test CD (Police, Synchronicity, catalog# 0082839373524) I get (in part): TRACK 01

Why do I see this error? > library(stats) > require(stats) [1] TRUE > > tHSD <- TukeyHSD(aov) Error in TukeyHSD(aov) : no applicable method for "TukeyHSD" In case it helps: > aov Call: aov(formula = roi ~ (Cue * Hemisphere) + Error(Subject/(Cue * Hemisphere)), data = roiDataframe) Grand Mean: 8.195069 Stratum 1: Subject Terms: Residuals Sum