[R] melting a data frame

[Data Analytics Corp.]

Hi,

Suppose I have a data frame with 189 columns.  The columns are actually 
9 blocks of 21 columns each, each block representing measures on each of 
9 products.  There are 130 rows.  Suppose I extract the first block of 
21 columns and make them into a separate data frame.  I then want to 
take the second block of 21 columns and rbind it to the first; then the 
third set of 21 and rbind it to the first two; etc.  The final data 
frame should have 1170 (= 9 * 130)  rows and 21 columns.  Is there an 
easy way to melt the blocks comparable to using the melt function in the 
plyr package (which is why I'm referring to what I want to do as 
"melting")?  It seems that there should be a simple way to do this.  I 
used a for loop which worked, but I want to see if there's a more 
efficient way.

Thanks,

Walt

________________________

Walter R. Paczkowski, Ph.D.
Data Analytics Corp.
44 Hamilton Lane
Plainsboro, NJ 08536
________________________
(V) 609-936-8999
(F) 609-936-3733
walt at dataanalyticscorp.com
www.dataanalyticscorp.com