Re: [R] Group several variables and apply a function to the group

2011-12-04 Thread Bert Gunter
... with() is useful here: e.g. in base R, simply tapply() or ave() with with() with(df,ave(x, comn,mi, FUN = sd)) -- Bert On Sun, Dec 4, 2011 at 1:07 PM, John Kane wrote: > ?aggregate should do it > > aggregate(df$x,list(df$comn, df$mi), sd) > > There are other ways of course > > Using the

Re: [R] Group several variables and apply a function to the group

2011-12-04 Thread John Kane
?aggregate should do it aggregate(df$x,list(df$comn, df$mi), sd) There are other ways of course Using the reshape2 package library(reshape2) x1 <- melt(df, id=c("comn", "mi")) dcast(x1, comn + mi ~ variable, sd) --- On Sun, 12/4/11, Aurélien PHILIPPOT wrote: > From: Aurélien PHILIPPOT >

Re: [R] Group several variables and apply a function to the group

2011-12-04 Thread Pete Brecknock
Aurélien PHILIPPOT wrote > > Dear R-experts, > I am struggling with the following problem, and I am looking for advice > from more experienced R-users: I have a data frame with 2 identifying > variables (comn and mi), and an output variable (x). comn is a variable > for > a company and mi is a va

Re: [R] Group several variables and apply a function to the group

2011-12-04 Thread Aurélien PHILIPPOT
exactly like that! thanks a lot. Aurelien 2011/12/4 Felipe Carrillo > Like this? > library(plyr) > ddply(df,.(comn,mi),summarise,stDEV=sd(x)) > > Felipe D. Carrillo > Supervisory Fishery Biologist > Department of the Interior > US Fish & Wildlife Service > California, USA > http://www.fws.gov/

Re: [R] Group several variables and apply a function to the group

2011-12-04 Thread Felipe Carrillo
 Like this? library(plyr) ddply(df,.(comn,mi),summarise,stDEV=sd(x)) Felipe D. Carrillo Supervisory Fishery Biologist Department of the Interior US Fish & Wildlife Service California, USA http://www.fws.gov/redbluff/rbdd_jsmp.aspx From: Aurélien PHILIPPOT >To: R-help@r-project.org >Sent: Sunda