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Dear All, I want to create a dataset for a NONMEM simulation. I have a dataframe with individual PK parameters and want to create a dosing sceinario in a second dataframe. I want to merge them both so that every individiual's PK parameters are combined with the dosing scenario into one. I do not have a common variable to merge and cbind is giving error that lengths are different. I

Dear Group, I am working with a large dataset where I need to select for each unique id the the unique lastpk row. Here is a sample subject: id wtdt wt lastpk 64050256 2010-09-18 275 2010-09-16 64050256 2010-09-19 277 2010-09-18 64050256 2010-09-20 272 2010-09-18 64050256 2010-09-21 277 2010-09-18 I want the result as:

Dear R group, I am trying to plot uisng a for loop. Here is the script: for (i in unique(cfn$ID)){ plot(cfn$TIME[cfn$ID==i],cfn$DV[cfn$ID==i],pch=16)} I could access only the last plot of the series and cannot go back to see all the plots. I appreciate your help in resolving this issue and also please suggest how I can export the plots as a pdf or other format files for publication purposes.

Dear Group, I have the following dataset: ID REPI DV CONC SS 1 1 156.84 116 0 1 2 146.56 116 0 1 3 115.13 116 0 1 4 207.81 116 0 1 5 129.53 116 0 1 6 151.48 116 0 1 7 158.95 116 0 1 8 192.37 116 0 1 9 32.97 116 0 1 10 151.66 116 0 I want to calculate the percentile of each CONC within ID=i and add as a column

Dear Group, I have a problem with time date formatting. I have Date and Time in different columns in a .csv file and want to have a column with Date and Time together. I could format the date into the right mode using strptime and as.Date functions. I am not able to do that with TIME column. I appreciate your help in solving this issue. Currently the TIME column is in character mode.

Dear group, I need help on two problems: 1. I am trying to plot density plots for each individual in 8 occasions. I can do this by subject wiht the code below: par(mfrow=c(4,2)) plot(density(all8scenarios$SIMCONC[all8scenarios$ID==1&all8scenarios$WSEQ==0])) plot(density(all8scenarios$SIMCONC[all8scenarios$ID==1&all8scenarios$WSEQ==1]))

Dear group, I am trying to prepare a NONMEM friendly dataset for population PK analysis. My patient IDs are 10 digit long and NONMEM is losing precison and rouding the last couple of digits. I need to generate unique Patient IDs fromt he current 10-digit IDs. Ihave total 250 subjects so I appreciate if anybody can suggest me a way to code this in R. Regards, Ayyappa [[alternative HTML