On Mon, 2007-02-19 at 16:10 +1300, Amy Whitehead wrote: > Hi, > > I am looking for a way to randomly extract a specified number of rows from a > data frame. I was planning on binding a column of random numbers to the > data frame and then sorting the data frame using this bound column. But I > can't figure out how to use this column to sort the entire data frame so > that the content of the rows remains together. Does anyone know how I can > do this? Hints for other ways to approach this problem would also be > appreciated. > > Cheers > Amy
See ?sample Using the 'iris' dataset in R: # Select 2 random rows > iris[sample(nrow(iris), 2), ] Sepal.Length Sepal.Width Petal.Length Petal.Width Species 96 5.7 3.0 4.2 1.2 versicolor 17 5.4 3.9 1.3 0.4 setosa # Select 5 random rows > iris[sample(nrow(iris), 5), ] Sepal.Length Sepal.Width Petal.Length Petal.Width Species 83 5.8 2.7 3.9 1.2 versicolor 12 4.8 3.4 1.6 0.2 setosa 63 6.0 2.2 4.0 1.0 versicolor 80 5.7 2.6 3.5 1.0 versicolor 49 5.3 3.7 1.5 0.2 setosa HTH, Marc Schwartz ______________________________________________ R-help@stat.math.ethz.ch 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.
