Le 17/06/10 06:44, ZZY ZYBOYS a écrit :
Dear all:
I have a question regarding on how to take the lower triangular part from a
full matrix.
for example
1 2 3 1 0 0
3 4 5 to 3 4 0
7 8 9 7 8 9
Thanks,
Joey
Please take at least the time to send a reproducible example on how you
make you data, i.e:
> x <- matrix( 1:9, nr = 3, byrow = T )
See ?lower.tri
> x[ upper.tri(x) ] <- 0
Or see ?row and ?col
> x[ row(x) < col(x) ] <- 0
Also note that ??triangular finds lower.tri
Romain
--
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
|- http://bit.ly/98Uf7u : Rcpp 0.8.1
|- http://bit.ly/c6YnCi : graph gallery collage
`- http://bit.ly/bZ7ltC : inline 0.3.5
______________________________________________
[email protected] 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.
