R help..subsetting data frame that meeting multiple criteria
On Nov 23, 2012, at 1:14 PM, prasmas wrote:
Hi, I am new to R. I am trying to regroup data frame using multiple constrains. for example data frame: data value class percent 15526 36 4.6875 15527 62 85.9375 15527 82 32.4564 15528 36 70.3125 15528 62 9.375 15528 82 74.6875 I need to regroup each class that have greater than or equal to 70 percent into new group. Similarly, I also need to regroup each class that have less than 70 percent into new group. I can do this by using following syntax for each class class36<- data[data$class==36&data$percent>70,] class36a<- data[data$class==36&data$percent<=70,] but I have 100 different classes. In order to do this for all 100 classes, I have write that syntax 100 times. There would be some way to do dynamically to regroup for 100 classes (may be using for loop) but I dont know. Can you please help in this. Output should be like data frame: class36 value class percent 15528 36 70.3125 data frame: class36a value class percent 15526 36 4.6875
> dat.a <- dat[ dat[["class"]] %in% dat[ dat[["percent"]] >70,
"class"] , ]
> dat.a
value class percent
1 15526 36 4.6875
2 15527 62 85.9375
3 15527 82 32.4564
4 15528 36 70.3125
5 15528 62 9.3750
6 15528 82 74.6875
> row.names(dat.a) <- unlist(tapply(dat.a$class, dat.a$class,
function(x) paste0(x, letters[1:length(x)])))
> dat.a
value class percent
36a 15526 36 4.6875
36b 15527 62 85.9375
62a 15527 82 32.4564
62b 15528 36 70.3125
82a 15528 62 9.3750
82b 15528 82 74.6875
You can split by the NROW of dat.a if you want.
David. > > data frame: class62 > 15527 62 85.9375 > > data frame: class62a > 15528 62 9.375 > > data frame: class82 > 15528 82 74.6875 > > data frame: class82a > 15527 82 32.4564 > > Thank you very much your help.. > P. > > > > -- > View this message in context: http://r.789695.n4.nabble.com/R-help-subsetting-data-frame-that-meeting-multiple-criteria-tp4650601.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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 Alameda, CA, USA