I am trying to get R to randomly select values from my dataset (i.e. bootstrapping) with replacement. However, my attempts at this have been unsuccessful. Here is a basic example of what I am doing: I have a data vector of 8 values (i.e. data= 2,5,9,4,5,6,7,8). I used the sample function and it worked. However, it only repeated my values in the exact same order as the dataset. It did not randomly sample them. Here the code for what I did: sample(data, replace=TRUE) Any advice to randomly select data from my dataset would be greatly appreciated. Mike [[alternative HTML version deleted]]
On Tue, Sep 28, 2010 at 6:22 PM, Michael Larkin <mlarkin at rsmas.miami.edu> wrote:> I am trying to get R to randomly select values from my dataset (i.e. > bootstrapping) with replacement. ?However, my attempts at this have been > unsuccessful. ?Here is a basic example of what I am doing: > > I have a data vector of 8 values (i.e. data= 2,5,9,4,5,6,7,8). ?I used the > sample function and it worked. ?However, it only repeated my values in the > exact same order as the dataset. ?It did not randomly sample them. ?Here the > code for what I did: > > sample(data, replace=TRUE)You're doing the right thing. Perhaps your random seed was set in a particular way, or perhaps you made some mistake in the execution, but I get the following:> data= c(2,5,9,4,5,6,7,8) > sample(data, replace=TRUE)[1] 5 5 5 4 9 8 2 7 which is what you likely want. Peter
Mike, It works for me:> data <- 1:8 > sample(data,replace=TRUE)[1] 6 4 5 2 5 8 7 2 Please provide a reproducible example, if possible, and the output of sessionInfo(). Jonathan On Tue, Sep 28, 2010 at 7:22 PM, Michael Larkin <mlarkin@rsmas.miami.edu>wrote:> I am trying to get R to randomly select values from my dataset (i.e. > bootstrapping) with replacement. However, my attempts at this have been > unsuccessful. Here is a basic example of what I am doing: > > I have a data vector of 8 values (i.e. data= 2,5,9,4,5,6,7,8). I used the > sample function and it worked. However, it only repeated my values in the > exact same order as the dataset. It did not randomly sample them. Here > the > code for what I did: > > sample(data, replace=TRUE) > > Any advice to randomly select data from my dataset would be greatly > appreciated. > > Mike > > > > > [[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. >[[alternative HTML version deleted]]