Re: [R] as.Date question

Look at documentation ?as.Date as.Date first represents time in UTC, what gives: as.POSIXlt(zzz1, tz="UTC") HTH 2009/12/20 MAL : > All! > > This piece of code: > > zzz1 <- as.POSIXct("1999-03-18", tz="CET") > zzz2 <- as.POSIXlt("1999-03-18", tz="CET") > zzz1 == zzz2 > as.Date(zzz1) > as.Date(z

[R] Fwd: conditionally merging adjacent rows in a data frame

I've also made some comparisons and taking into account execution time, sqldf wins. SummaryBy is better then aggregate in some specific situations I met in practice. I present this situation below. It assumes, that there are at least two groups with high number of levels. n<-10; grp1<-sample(1

Re: [R] conditionally merging adjacent rows in a data frame

I've sent last message only to Titus. Sorry :) Below my proposition: Instead of aggregate, try summaryBy from doBy package. It's much faster. And this package made my life easier :) try: summaryBy(dur+x~index, data=d, FUN=c(sum, mean)), but index should be in data.frame as I remember. I haven't

Re: [R] bootstrap help

tally can't follow that line. > the result is a 50 by 2 table. > what is that? is a sample? > > Thanks. > > casper > > > > > Marek Janad wrote: >> >> data<-data.frame(x=rnorm(49), y=rnorm(49)) >> t(sapply(1:50,function(i){colMeans(data[sample(

Re: [R] bootstrap help

data<-data.frame(x=rnorm(49), y=rnorm(49)) t(sapply(1:50,function(i){colMeans(data[sample(nrow(data),size=nrow(data),replace=TRUE),])})) r-help@r-project.org 2009/12/7 casperyc : > > Hi there, > > i think that's not what i was aiming for... > > i was aked to > > Generate 50 Bootstrap samples and

Re: [R] how to fetch rows with certain characteristics

Try > x <- read.table(textConnection( + "1.2 1 + 1.2 1 + 1.3 1 + 1.5 1 + 1.1 2 + 1.2 2 + 9.9 2 + 0.1 3 + 1.1 3 + 1.9 3") ) > x.min <- tapply(x[,1], x[,2], min) > x[x.min[x[,2]]==x[,1],] V1 V2 [1,] 1.2 1 [2,] 1.2 1 [3,] 1.1 2 [4,] 0.1 3 2009/10/29 Ista Zahn > I still don't under