zcatav <zcatav <at> gmail.com> writes: > > Your suggestion works perfect as i pointed previous message. Now have another > question about data editing. I try this code: > X[X[,"c"]==1,"b"]<-X[,"d"] > and results with error: `[<-.data.frame`(`*tmp*`, X[, "c"] == 1, "b", value > = c(NA, : > replacement has 9 rows, data has 2 >
is this equivalent and/or preferred to: X$b[X$c==1]<-X$d[X$c==1] ?? I assume this goes back to the various indexing methods for a dataframe, an object vector that is a column of a data frame vs. an object data frame that happens to be one column of a larger data frame. on a very large data set is one preferable for speed? one for memory use? I tend to index using $ operators often and if I should quit let me know!! Thanks, Justin > Logically i selected 2 rows with X[,"c"]==1. Than i want to replace in that > rows its own data from "d" to "b" with X[,"b"]<-X[,"d"]. What is wrong? > > -- > View this message in context: http://r.789695.n4.nabble.com/conditional-data-replace-recode-change-or-whatsoever-tp3714715p3715218.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.
