[R] an error in nlme package

Dear All,I am trying to fit one compartment IV bolus model on pharmacokinetic data using phenoModel function in nlme package, based on a tutorial entitled   "Development of population PK model using R- Case study I". The codes are as fallowing: library(nlme)mydata.grp <- groupedData(CONC~TIME|CID

[R] A question about nlmer in lme4 package

Dear all,I have studied “Mixed models in R using the lme4 package Part 6: Nonlinear mixed models” by Douglas Bates. In this tutorial, there are some codes to fit nonlinear mixed models for Theoph data. The codes are as fallows:  >Th. start <- c(lKe = -2.5, lKa = 0.5 , lCl = -3)> nm1 <- nlmer ( co

[R] multivariate normal distribution

Dear every one I want to generate 10 vector of multivariate normal distribution(means are zero and the size of the vectors is 40). correlation among these variables is     |0.5| ^(i-j)   , i,j=1,...,10. How can I generate these vectors?Thanks in advanceElham [[alternative HTML version de

[R] How do I separate elements of a vector by comma?

I have a vector like this (this vector is a colomn of a data set): > 3 5 2 3 7 4 7 8  8 9 0 1 4 I want to separate elements of the vector by comma like this: > 3,5,2,3,7,4,7,8,8,9,0,1,4 How can do this? Thanks. Elham [[alternative HTML version deleted]] ___

[R] converting a coloumn in a data set to a vector

Hi every one, I have a simple question. I want to make a vector from one of  the colomns in a data set. for example I have this data: x1 x2 x3 1   5   7 4   8   9 8    6  12 4   8   13  I want to convert x1 to a vector such as: x1= c(1,4,8,4) How I can do it? Thanks [[alternative HTML vers

[R] how do I separete coloumns by comma?

Hi every one, I have a text file like this: 1    4   4    1    6    23 1   4    2    2    3    28 1    4    5    1    2    24 1    2    3    1    1    24 1   2    3    1    2     40 1   2   3    1    4      22 I want to separate columns by comma, like this: 1,4,4,1,6,23 1,4,2,2,3,28 1,4,5,1,2,24 1

[R] multivariate multilevel model

Hi I want to fit a multivariate multilevel model for a longitudinal data set. can you introduce me a package or some function to fit this model? Thanks in advance. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https:/

[R] a question

HiI have a question, Is there a package to do counting process in survival analysis with R? [[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 h