search for: liulei

Hi there, I want to make trajectory plots for data as follows: ID time y 1 1 1.4 1 2 2.0 1 3 2.5 2 1.5 2.3 2 4 4.5 2 5.5 1.6 2 6 2.0 ... That is, I will plot a growth curve for each subject ID, with y in the y axis, and time in the x axis. I would like to have all growth curves in the same plot. Is there

...status) ~ rx+x2, data=rats2, random=~ (1+x2)|litter ) Lei Liu Assistant Professor Division of Biostatistics and Epidemiology Dept. of Public Health Sciences School of Medicine University of Virginia 3181 Hospital West Complex Charlottesville, VA 22908-0717 1-434-982-3364 (o) 1-434-806-8086 (c) liulei at virginia.edu ll9f at virginia.edu

...it, like vcov() for the variance estimate? Thanks! Lei Liu Assistant Professor Division of Biostatistics and Epidemiology Dept. of Public Health Sciences School of Medicine University of Virginia 3181 Hospital West Complex Charlottesville, VA 22908-0717 1-434-982-3364 (o) 1-434-806-8086 (c) liulei at virginia.edu ll9f at virginia.edu

...or there is some update on this function. Thanks! Lei Liu Assistant Professor Division of Biostatistics and Epidemiology Dept. of Health Evaluation Sciences School of Medicine University of Virginia 3181 Hospital West Complex Charlottesville, VA 22908-0717 1-434-982-3364 (o) 1-734-730-1395 (c) liulei at virginia.edu ll9f at virginia.edu

...Can nlme do the work? Thanks! Lei Liu Assistant Professor Division of Biostatistics and Epidemiology Department of Public Health Sciences School of Medicine University of Virginia 3181 Hospital West Complex Charlottesville, VA 22908-0717 1-434-982-3364 (o) 1-434-806-8086 (c) 1-434-243-5787 (f) liulei at virginia.edu ll9f at virginia.edu

> Message: 4 > Date: Sun, 27 Jun 2004 03:18:43 -0400 > From: Lei Liu <liulei at l.imap.itd.umich.edu> > Subject: [R] help in R calling C function > To: r-help at stat.math.ethz.ch > Message-ID: <5.1.0.14.1.20040627030746.014936b8 at l.imap.itd.umich.edu> > Content-Type: text/plain; charset="us-ascii"; format=flowed > > Hi there, > &...

------------- Begin Forwarded Message ------------- Date: Wed, 5 Jul 2006 09:09:14 -0500 (CDT) From: Terry Therneau <therneau at mayo.edu> Subject: RE: Problem with coxme To: jhz22 at medschl.cam.ac.uk Cc: R-help at stat.mat.ethz.ch, liulei at virginia.edu, spencer.graves at pdf.com Content-MD5: BXKVsHtW/1I9mIUqrXBU0g== The original question involved a strange error message from coxme when trying to fit a random slopes model: coxme(Surv(time, status) ~ rx+x2, data=rats2, random=~ (1+x2)|litter) Synopsis a. coxme do...

Hi there, I want to install the "adapt" package, which is available at http://cran.r-project.org/src/contrib/Archive/adapt/. This package cannot be directly installed by "install packages" menu in R. So I downloaded the zip file into the hard drive. But I couldn't install it using "install packages from local zip files". I also tried to unzip these files in

Hi there, I have two questions on matrix manipulation. For the first one, I want to calculate the product of each column of a matrix (say A) with another vector (say b). That is, if A has 5 columns (a1, a2, a3, a4, a5), I want to obtain a matrix with columns (a1*b, a2*b, aA3*b, a4*b, a5*b). Can I do it directly, without using "for" loop? For the second one, I have a matrix A of

Hi there, I try to compare the mixed model package "lme" by Splus and R. I used the dataset "Ovary" and the following code assuming AR(1) model for the error term: lme(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), data=Ovary, random = pdDiag(~sin(2*pi*Time) ) , correlation=corAR1() ) But I got different results! And then I used a simpler model: lme(follicles ~

...reproducible code. > > -- Do you know how to read? http://www.alienetworks.com/srtest.cfm http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader Do you know how to write? http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail --Forwarded Message Attachment-- From: liulei at virginia.edu To: r-help at r-project.org Date: Mon, 23 Aug 2010 15:58:27 -0400 Subject: [R] trajectory plot (growth curve) Hi there, I want to make trajectory plots for data as follows: ID time y 1 1 1.4 1 2 2.0 1 3 2.5 2 1.5 2.3 2...

...e.com> Liu Shuo <shuo.liu@freescale.com> Liu Shuo <soniccat.liu@gmail.com> Liu ShuoX <shuox.liu@intel.com> Liu Ying <emoly.liu@intel.com> Liu Ying <Ying.Liu@freescale.com> Liu Yu <yu.liu@freescale.com> Liu, Jinsong <jinsong.liu@intel.com> liulei <lewis.liulei@huawei.com> Liviu Dudau <liviu.dudau@arm.com> Liz Clark <liz.clark@hp.com> Loc Ho <lho@apm.com> Loic Pallardy <loic.pallardy@stericsson.com> Lokesh Vutla <lokeshvutla@ti.com> Long Li <longli@microsoft.com> LongX Zhang <longx.z...

...e.com> Liu Shuo <shuo.liu@freescale.com> Liu Shuo <soniccat.liu@gmail.com> Liu ShuoX <shuox.liu@intel.com> Liu Ying <emoly.liu@intel.com> Liu Ying <Ying.Liu@freescale.com> Liu Yu <yu.liu@freescale.com> Liu, Jinsong <jinsong.liu@intel.com> liulei <lewis.liulei@huawei.com> Liviu Dudau <liviu.dudau@arm.com> Liz Clark <liz.clark@hp.com> Loc Ho <lho@apm.com> Loic Pallardy <loic.pallardy@stericsson.com> Lokesh Vutla <lokeshvutla@ti.com> Long Li <longli@microsoft.com> LongX Zhang <longx.z...

Hi there, I have a dataset from a longitudinal study with a lot of drop-out. I want to implement the inverse probability weighting method by Robins 1995 JASA paper "Analysis of semiparametric regression models for repeated outcomes in the presence of missing data". Does anyone know if there is a package to do it in R (or other software)? Thanks a lot! Lei

Hi there, I want to call a C function in R. I have some experience on it, but this time I need to call another C function in the "main" C function. As a simple example, I use the following C code: #include <stdio.h> #include <math.h> #include <stdlib.h> #include <time.h> void main(double *alpha) { double test(); double beta; beta= *alpha *2 +

Hi there, I have a question on how to extract the linear term in the penalized spline in coxph. Here is a sample code: n=100 set.seed(1) x=runif(100) f1 = cos(2*pi*x) hazard = exp(f1) T = 0 for (i in 1:100) { T[i] = rexp(1,hazard[i]) } C = runif(n)*4 cen = T<=C y = T*(cen) + C*(1-cen) data.tr=cbind(y,cen,x) fit=coxph(Surv(data.tr[,1],

Hello, I need to call an C function MH.c in my R code in Windows XP. I downloaded the software form http://www.stats.ox.ac.uk/pub/Rtools/ and installed them. But when I run the command "..\bin\Rcmd SHLIB MH.c", I got message "perl is not recognized as and internal or external command, operable program or batch file". How should I do? As a newbie, I just wonder if there is

Hi there, I am reading the 2004 paper "Smoothing with mixed model software" in Journal of Statistical Software, by Ngo and Wand. I tried to run their first example in Section 2.1 using R but I had some problems. Here is the code: library(nlme) fossil <- read.table("fossil.dat",header=T) x <- fossil$age y <- 100000*fossil$strontium.ratio knots <-