[R] a question on matrix manipulation

[Simon Blomberg]

How about this:

> mat <- matrix(rep(1:4, each=4), nrow=4, byrow=TRUE)
> mat[rep(1:4, times=c(3,2,4,5)),]

Cheers,

Simon.

On Wed, 2009-06-17 at 01:54 -0400, Lei Liu wrote:
> Hi there,
> 
> I have a question on manipulating a matrix. Say I have a matrix A 
> with 3 rows. I want to generate a new matrix B with 3 duplicates of 
> the first row of A, 2 duplicates of the second row, and 4 duplicates 
> of the third row. So B is a matrix with 9 rows. Or more general, I 
> want to generate (3, 2, 4, 5) duplicates of rows 1-4 of a matrix with 
> 4 rows. Is there a simple function to do it? Thanks a lot!
> 
> Lei
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
-- 
Simon Blomberg, BSc (Hons), PhD, MAppStat. 
Lecturer and Consultant Statistician 
School of Biological Sciences
The University of Queensland 
St. Lucia Queensland 4072 
Australia
Room 320 Goddard Building (8)
T: +61 7 3365 2506
http://www.uq.edu.au/~uqsblomb
email: S.Blomberg1_at_uq.edu.au

Policies:
1.  I will NOT analyse your data for you.
2.  Your deadline is your problem.

The combination of some data and an aching desire for 
an answer does not ensure that a reasonable answer can 
be extracted from a given body of data. - John Tukey.