[R] clusterCall with replicate function

I am trying to run a monte carlo process using snow with a MPI cluster. I have ~thirty processors to run the algorithm on and I want to run it 5000 times and take the average of the output. A very simple way to do this is to divide 5000 by the number of processors to get a number n and tell

[R] offset in coxph

The offset argument used in glm and other functions seems to have been removed from the argument list for coxph. I am wondering if there is a reason for this and if there is a possible work-around in order to produce a cox-ph object without fitting coefficients? Thanks, Mike

[R] justRMA

I am trying to preprocess a large dataset of affymetrix data. Creating an affybatch is not possible with the computer I am running it on, so I have used the justRMA command to run RMA. I have read the affy document describing the justRMA command and the help documentation but I am unclear as

[R] Access Rows in a Data Frame by Row Name

I have created a data frame using the read.table command. I want to be able to access the rows by the row name, or a vector of row names. I know that you can access columns by using the data.frame.name$col.name. Is there a way to access row names in a similar manner? [[alternative