similar to: Effect of data set size on calculation

Dear forumities, It's seem that there is no straight forward way to calculate R2 of a cluster solution in R. So, I would like to know if I'm right when calculating a R2-like statistic for a given clustering solution. In fact, I have different cluster solution for a given set of data. I would like to know which cluster solution gives the highest R2. My data (5 variables) are scaled to a 0

Hi - I apologize for the 2nd post, but I think my question from a few weeks ago may have been overlooked on a Friday afternoon. I might be missing something very obvious, but is it widely known that the aggregate function handles missing values differently depending if a data frame or a formula is the first argument ? For example, (d<- data.frame(sex=rep(0:1,each=3),

Hi, I'm just getting started with R and I'm having problems with some simple operations: I want to get the the sum of the column "SStot" for each year using the function by. The data set is named "SS". I've tried this: by (SS, year, sum(SStot)) and it's not working. Is it because there's a different number of rows for each year? How else can I do

I have been trying to produce a histogram that has two groups (male and female snakes) on the same graph (either superimposed or each frequency bar appears side by side). I found a couple of functions for superimposed histogram written by other people. The below is the codes I used for my data containing a column of svl (body size; snout-vent length) and another column of sex (male or female).

Hello all, I recently purchased a Cisco 7940 IP phone to do some testing with (to validate a migration to asterisk for our internal PBX needs). I understand that I need to update the phone for it to support SIP, so I configured the phone with an IP address and pointed it at my tftp server. When I reboot the phone I am currently getting "TFTP File Not Found SEPDefault.cnf" in the

Hi all, I have to transfer thousands of files across my network. We are looking at using rsync via a squid proxy to help improve the network tuning. What I am witnessing now is that with each successive file, the transfer speed resets to 0 and ramps up to 2.5MB/s. Is there anyway that I can group these transfers together to take better advantage of our bandwidth? I should be able to peak at

Hi all, I am interested at using a web proxy to help speed a transfer across a WAN. Are there any examples of syntax for the RSYNC_PROXY command available? Thanks, Max -- Max Clark <maxc at beast.clarksys.com> My Blog http://www.clarksys.com >> spamtrap: spam@clarksys.com - do NOT ever send email to this address <<

Hei, i am trying to plot the means of two variables (d13C and d15N), by 2 grouping factors (Species and Year) that i obtained by the function tapply. I would like to plot with different colours according to the Year and show the "Species" as data labels. My data looks like this: Species d13C d13N Year "Species1" 14,4 11.5 2009 "Species2"

Dear R-users, dear Prof. Ripley as package maintainer I tried to investigate the odd error, when I call nnet together with a 'weights' parameter, using the 'fgl' example in V&R p 348 The error I get is: Error in eval(expr, envir, enclos) : Object "w" not found I think it is a kind of scoping problem, but I really cannot see, what the problem exactly is. and

Dear R-users I use nnet for a classification (2 classes) problem. I use the code CVnn1, CVnn2 as described in V&R. The thing I changed to the code is: I define the (class) weight for each observation in each cv 'bag' and give the vector of weights as parameter of nnet(..weights = weight.vector...) Unfortunately I get an error during some (but not all!) inner-fold cv runs:

I hope this question is adequate for this list I use the nnet code from V&R p. 348: The very nice and general function CVnn2() to choose the number of hidden units and the amount of weight decay by an inner cross-validation- with a slight modification to use it for classification (see below). My data has 2 classes with unequal size: 45 observations for classI and 116 obs. for classII With

Hi All, I am trying to use a neural network for my work, but I am not sure about my approach to select a parsimonious model. In R with nnet, the IAC has not been defined for a feed-forward neural network with a single hidden layer. Is this because it does not make sens mathematically in this case? For example, is this pseudo code sensible? Thanks in advance for your help. I am sorry if this

Greetings: In R parallel's vignette, there is a comment "It would however take only slightly more work to allocate a stream to each task." (p.6). I've written down a working example that can allocate not just one, but several separate seeds for each task. (We have just a few project here that need multiple streams). I would like to help work that up for inclusion in the

Full_Name: Martha Nason Version: 2.0.1 OS: Windows XP Submission from: (NULL) (137.187.154.154) I am running simulations using fisher's test on 2 x c tables and a very small p.value from fisher's test (<2.2e-16) is returned as a negative number. Code follows. > set.seed(0) > nreps.outer <-7 > pvalue.fisher <- rep(NA,nreps.outer) > > population1 <- c(

Recently, I was working with some lagged designs where a vector of observations at one time was used to predict a vector of observations at another time using a lag 1 design. In the work, I noticed a lot of negative correlations, so I ran a simple simulation with 2 matched points. The crude simulation example below shows that the correlation can be -1 or +1, but interestingly if you do this

I am new to R and I am trying to do a monte carlo simulation where I generate data and interject error then test various cut points; however, my output was garbage (at x equal zero, I did not get .50) I am basically testing the performance of classifiers. Here is the code: n <- 1000; # Sample size fitglm <- function(sigma,tau){ x <- rnorm(n,0,sigma) intercept <- 0 beta

Dear R-devel, A user reported a strange problem with predict.randomForest in the randomForest package yesterday, and I'm baffled by it. The code at the end of the message produces the error. The problem is that, in predict.randomForest, there's a .Fortran call to "runforest". One of the arguments passed in is "countts", which is a vector of doubles. The error

Hello Everyone, *Question: *How do you calculate the sum of squares for a two-way _unbalanced_ ANOVA? *What I have done:* I have found many useful tutorials online for running a balanced two-way ANOVA but I haven't had much luck for running a unbalanced two-way ANOVA. From what I have read, the trouble with running an unbalanced two-way ANOVA, is that things get tricky when calculating

Earlier, I posted the following question: I want to superimpose histograms from three populations onto the same graph, changing the shading of the bars for each population. After consulting the help files and the archives I cannot find out how to do this (seemly) simple graph. To be clear, I want - a single x axis (from -3 to 18) - three groups of bars forming the histograms of each population

In a C++ extension to R (v 1.8.1), I've been experimenting with a generic "push back" function to tack one value at a time onto the end of an R vector created within the extension. After calling this function a certain number of times Rgui.exe (I'm writing in Windows using Visual Studio .NET 2003) will fail with an Access Violation, which doesn't happen when I pre-allocate