[R] 2 simple doubts
ramasamy at stats.ox.ac.uk
Wed Jul 10 12:23:13 CEST 2002
> 1) I couldn't discover what is the command for a concatenation of 2
> variable strings.
You can use c, cbind, rbind. Example follow :
x <- c(1,2,46) which returns you a vector of length 3 containing the number
if you have a numerical matrix of say X, Y, Z each of dim 10 by 2
then A <- cbind(X,Y,Z) binds the colums together to give a matrix of 10
or B <- rbind( X,Y,Z) binds the rows together to give a matrix of 30
If some of your vectors are non-numerical, then you may have to use the
data.frame option instead.
> 2) For example, if I have three variable strings, and each one has the
> name of a variable in a data matrix:
> , is it possible to construct a command like this:
> , that would do the job of tree(V1~V2+V3,data=DS1) ?
Hmm, I am not quite sure what you are asking but you best try with a small
manage matrix first.
I think you are trying the change the names of your columns right ? If so
colnames(DS1) <- c( "a", "b", "c")
Note the quotes around a,b, c. Thus you need not to extract each vector by
Again for dataframes, the naming procedure is slightly different. refer to
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
More information about the R-help