[R] code that will use two data sets which differ in size.

Hi all, This is a really basic question but I can't figure it out. I am trying to write a piece of code that will  use two datasets, z and m.. This code is meant to assign the mean of selected values in dataset m to a new column z$c in datset z but the rows and columns of the two data sets diffe

[R] Import from excel 2007

Hey Seniors, Really new to R, please has anyone imported a dataset from MS office excel 2007 into R yet? It seem to be giving me hard times which I did not expect as it use to go well with the previous versions. Thanks in advance. arnoldo -