Hi: Using Michael's example data, here's another approach:
x = data.frame(x = 1:5) y = data.frame(y = 1:10) z = data.frame(z = 1:3) # Generate a vector to name the list components nms <- c('x', 'y', 'z') # Combine data frames into a list L <- list(x, y, z) # name them names(L) <- nms # Use lapply() to get the number of rows in each component data frame as.data.frame(lapply(L, nrow)) x y z 1 5 10 3 HTH, Dennis On Tue, Sep 20, 2011 at 11:23 AM, Vining, Kelly <kelly.vin...@oregonstate.edu> wrote: > Hello R users, > I have a set of data frames for which I am tallying row numbers, as shown > below. > >> nrow(mC_Explant) > [1] 14480 >> nrow(mC_Callus) > [1] 23320 >> nrow(mC_RegenPlant) > [1] 8108 > > etc. > > I want to create a new data frame which has the variable names as column > headings, and then a single row with the nrow tallies. My first step was this: > > dfIntron <- c(nrow(mC_Explant), nrow(mC_Callus), nrow(mC_RegenPlant)) > > Then, to set the column names, I tried this, and got the following error: > > colnames(dfIntron) <- c("mC_Explant", "mC_Callus", "mC_RegenPlant") > Error in `colnames<-`(`*tmp*`, value = c("mC_Explant", "mC_Callus", > "mC_RegenPlant" : > attempt to set colnames on object with less than two dimensions > > Even my first step seems wildly inefficient, and obviously doesn't work. > There must be a simple way to do this, but I can't use table(), for example, > as there are multiple data frames. > > Any help will be appreciated. > > --Kelly V. > > > ______________________________________________ > 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. > ______________________________________________ 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.