You can use "[[", I think, as in
basin.param[[string.variable]]
or, eqivalently for a data frame
basin.param[, string.variable]
-roger
Dewez Thomas wrote:
Hi all,
I haven't been able to find how to assess a variable who's name is constructed with paste. The problem is following: In a data frame, there are 12 columns whose title vary only by a digit, all other part being equal. I would like to compute a operation on a subset these variables and parse them in turn.
the data frame "basin.param" contains columns called ratio1, ratio2, ratio3... in each of these ratios I want to retain only values above 0. This could be put like this
crit<- which(basin.param$ratio1 > 0) basin.param$ratio1[crit] + basin.param$val[crit]
OK, so what if I want to increment from ratio1 to ratio3 automatically and
return the value of the variable represented by the string? (does this make
sense?)
# Create the variable name for (i in 1:3){
string.variable <- paste("basin.param$ratio", index, sep="")
# What is the instruction to interpret the string.variable value ???
}
Cheers
Thomas *** Le contenu de cet e-mail et de ses pièces jointes est destin...{{dropped}}
______________________________________________ [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
______________________________________________ [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
