On Apr 26, 2010, at 11:27 AM, Gabor Grothendieck wrote:
Here are four ways:
# state.name comes with R
DF <- data.frame(state = state.name, num = seq_along(state.name))
DF[DF$state %in% c("Iowa", "Utah"),]
subset(DF, state %in% c("Iowa", "Utah"))
subset(DF, grepl("Iowa|Utah", state))
John;
The grepl implementation offers benefits that the %in% versions do
not, e.g. partial matches:
subset(DF, grepl("New+", state))
state num
29 New Hampshire 29
30 New Jersey 30
31 New Mexico 31
32 New York 3
Or equivalently and probably faster:
> DF[grepl("New+", DF$state), ]
This gives the state.names with any spaces:
> DF[grepl(". +", DF$state), ]
--
David.
library(sqldf) # see http://sqldf.googlecode.com
sqldf("select * from DF where state in ('Iowa', 'Utah')")
On Mon, Apr 26, 2010 at 11:12 AM, John Sorkin
<jsor...@grecc.umaryland.edu> wrote:
I would like to select rows if a row contains any one of several
values. I can do the selection as follows:
result[,"Subject"]=="JEFF" | result[,"Subject"]=="BG"
But this is very unwieldily if one wishes to select many, many rows
as one has to continuously repeat the source:
result[,"Subject"]=="JEFF" | result[,"Subject"]=="BG" |
result[,"Subject"]=="John" | result[,"Subject"]=="Mary"
Is there an easier way? I tried the following but it did not work:
result[,"Subject"]==c("JEFF" | "BG" | "John" | "Mary")
Thanks,
John
John David Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
(Phone) 410-605-7119
(Fax) 410-605-7913 (Please call phone number above prior to faxing)
Confidentiality Statement:
This email message, including any attachments, is for th...
{{dropped:6}}
______________________________________________
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.
______________________________________________
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.
David Winsemius, MD
West Hartford, CT
______________________________________________
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.
