Greg Snow-2 wrote:
"You are suffering from the fact that the longest distance between 2 points
is a shortcut.
The df$column notation is a shortcut for df[[column]] that has some nice
properties, but the shortcut gets in the way when you want to do something
more structured. Try qq1[[z]]==y and avoid all that pasting, parsing, and
evaluating. "
My response:
Unfortunately I find it to be not correct and unfortunately I see no way to
avoid pasting parsing and evaluating in order
to have functions that does simple things in R.
temp<-qq1[qq1$PrimaryConditionGroup=="AMI",]
has no error when
temp<-qq1[qq1[[PrimaryConditionGroup]]=="AMI",] cause the following error
announcement
"Error in (function(x, i, exact) if (is.matrix(i)) as.matrix(x)[[i]] else
.subset2(x, :
object 'PrimaryConditionGroup' not found"
I found no way to replace the function that was in the subject of this
thread by something simpler(and here is the function again)
> ugly<-function(y,z)
> {
> text1<-paste("temp<-qq1[qq1$",z,sep="")
> text1<-paste(text1,"==y",sep="")
> text1<-paste(text1,",]",sep="")
> eval(parse(text=text1))
> temp<<-temp
> }
--
View this message in context:
http://r.789695.n4.nabble.com/How-to-translate-string-to-variable-inside-a-command-in-an-easy-way-in-R-tp3645594p3664747.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
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.
