This is very helpful, Phil. Being new to R and trying to get a handle on *apply, by, aggregate... this is great. Thank you.
Jim -----Original Message----- From: Phil Spector [mailto:spec...@stat.berkeley.edu] Sent: Wednesday, December 08, 2010 2:36 PM To: Jim Moon Cc: r-help@r-project.org Subject: Re: [R] sd() for numeric row entries Jim - Suppose the data frame is named "df". Then df$std_dev = apply(df,1,sd,na.rm=TRUE) will do what you want, although it will generate some warning messages due to the first column. df$sd_dev = apply(df[,sapply(df,is.numeric)],1,sd) does the same, but won't produce warnings. - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu On Wed, 8 Dec 2010, Jim Moon wrote: > How might one calculate standard deviation, row-wise, for the numeric values > in a data frame such as this one > V1 V2 V3 V4 V5 > 1 rs11089130 0.4565 0.4574 0.4569 0.4572 > 2 rs738829 0.6548 0.6519 0.6448 0.6549 > 3 rs915674 0.7503 0.7500 0.7517 0.7502 > > and place the standard deviation in a 6th column called ???std_dev???? > > Regards, > Jim > > > [[alternative HTML version deleted]] ______________________________________________ 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.
