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Hi, I was wondering if someone know how to sort a data set by column. I've tried sort() but without luck. I would think there should be a function for it somewhere. An example with the iris data set...

Hi, I was wondering, if it is possible to print out the values of variables while you are in a for/while loop? Like this for example: for (i in 1:5) { i } So what I want is this as...

Hi, I am trying to use a vector of indices to select some rows from a matrix. But before I can do that I somehow need to convert 'combinations' into a list, since 'mode(combinations)' says it's 'numerical'. Any...

Dear Claudia, This is how I save the plots as *.eps. postscript(file="testplot.eps", paper="special", width=10, height=10, horizontal=FALSE) yvalues = runif(100) plot(yvalues) dev.off() HTH, Martin Lam --- paladini at rz.uni-potsdam.de wrote...

# row bind a <- matrix(1:5) a a <- rbind(a, 6) a # column bind b <- matrix(1:5) b b <- cbind(b, 6:12) b b <- cbind(b, 13) b Hope this helps, Martin --- Simone Gabbriellini <ogabbrie at tin.it...

Hi, I was wondering if it's possible to get the row numbers from a filtering. Here's an example: # give me the rows with sepal.length == 6.2 iris[(iris[,1]==6.2),] # output Sepal.Length Sepal.Width Petal...

Hi, I have a problem when I want to add new points (or a new line) to the graph. Some points (or parts of the line) are not shown on the graph because they lie beyond the scale of the...

Hi, Perhaps this is not the proper place to ask this question but I am out of options, therefore I apologize in advance. I want to know how the (upper bound?) generalization error of the random forest is determined using...

Dear Gueorgui, > Is it true that R generally cannot handle medium > sized data sets(a > couple of hundreds of thousands observations) and > threrefore large > date set(couple of millions of observations)? It depends on what you want to do with...

Hi, I have written a piece of code, which is a variant of the random forest (rf) package algorithm, entirely in R. I know that some of the code in the rf package is written in c or c++. The...

Hi, Perhaps you should try the transpose function t(). It converts a row into a column and vice versa. HTH, Martin Lam --- Michael <comtech.usa at gmail.com> wrote: > Hi all, > > I tended to use rbind, or cbind to force...

Hi, I was wondering if it is possible to get the rowindices without using the function "which" because I don't have a restriction criteria. Here's an example of what I mean: # take 10 randomly selected instances iris[sample...

# create a 4x4 matrix with random values smallmatrix = matrix(runif(16)*10, ncol = 4, nrow = 4) # get the row and column number of the item in the matrix with the highest value which(smallmatrix == max(smallmatrix), arr.ind = 1) HTH...

Dear mailinglist members, I was wondering if there was a way to re-evaluate the instances of a tree (in the forest) again after I have manually changed a splitpoint (or split variable) of a decision node. Here's an...

# to see the objects that are currently in memory objects() # to remove everything rm(list = ls()) HTH, Martin --- Luis Ridao Cruz <Luisr at frs.fo> wrote: > ?rm > > > >>> <v.schlecht at arcor.de> 13/09/2005 12:08:55 >>> > > Hi, I...

Type "?mean" and hit "enter" in the console to see the description of the function. # randomly draw 5 numbers between 1 and 10 without replacement randomlist = sample(1:10, 5) # calculate the mean of the list meanoflist = mean(randomlist) # show...

x <- array(1:20, dim = c(4, 5)) ind <- array(c(1:3, 3:1), dim = c(3, 2)) # instead of using ind (pairs of coordinates) for getting the items in the matrix, you can convert it to a list...

Hi, I will explain my problem with this example: library("randomForest") # load the iris plant data set dataset <- iris numberarray <- array(1:nrow(dataset), nrow(dataset), 1) # include only instances with Species = setosa or virginica indices <- t(numberarray[(dataset$Species...

Hi, I am somewhat new to R so this question may be foolish, but is it possible to add decision trees into a list, array or vector in R? I am trying to build a collection (ensemble) of decision trees...

Thank you for this and earlier help Mr. Ripley. Martin --- Prof Brian Ripley <ripley at stats.ox.ac.uk> wrote: > Look at ?"[.factor": > > finaldataset$Species <- > finaldataset$Species[,drop=TRUE] > > solves this. > > On Fri, 26 Aug 2005, Martin Lam wrote: > > > Hi...