On Jan 27, 2011, at 6:29 PM, Peter Jaksons wrote:
Hello,
I want to create a flexible code for the following example: In stead
of
using a different code for each n (as in my example below), I want to
write a general code for every n (n from 1 to 10).
Have you done any thinking about the size of hte programming task?
Perhaps running this code?
> 20^(1:10)
[1] 2.000e+01 4.000e+02 8.000e+03 1.600e+05 3.200e+06 6.400e+07
1.280e+09 2.560e+10 5.120e+11 1.024e+13
So you might want to think twice about trying for n > 6 right off the
bat/
expand.grid could be used:
col3 <- expand.grid(as.data.frame(matrix(rep(1:20, 3), ncol=3)))
col3[apply(col3, 1,sum)==20, ]
> nrow( col3[apply(col3, 1,sum)==20, ] )
[1] 171
--
David.
I tried a lot of things, but I always got stuck with the number of
subloops or witch closing the brackets. Any suggestions?
Cheers,
Peter
Department of Mathematics and Statistics
University of Canterbury
New Zealand
n <-2
matrixallo <- matrix(nrow=0,ncol=n)
for(i in 1:20)
{
for (j in 1:20)
{
if (i+j == 20)
{
newentry<- cbind(i,j)
matrixallo <- rbind(matrixallo,newentry)
}
}
}
n <-3
matrixallo <- matrix(nrow=0,ncol=n)
for(i in 1:20)
{
for (j in 1:20)
{
for (k in 1:20)
{
if (i+k+j == 20)
{
newentry<- cbind(i,j,k)
matrixallo <- rbind(matrixallo,newentry)
}
}
}
}
This email may be confidential and subject to legal privilege, it may
not reflect the views of the University of Canterbury, and it is not
guaranteed to be virus free. If you are not an intended recipient,
please notify the sender immediately and erase all copies of the
message
and any attachments.
Please refer to http://www.canterbury.ac.nz/emaildisclaimer for more
information.
[[alternative HTML version deleted]]
______________________________________________
R-help@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.
David Winsemius, MD
West Hartford, CT
______________________________________________
R-help@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.
