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Hi Folks, Given a series of n independent Bernoulli trials with outcomes Yi (i=1...n) and Prob[Yi = 1] = Pi, I want P = Prob[sum(Yi) = r] (r = 0,1,...,n) I can certainly find a way to do it: Let p be the vector c(P1,P2,...,Pn). The cases r=0 and r=n are trivial (and also are exceptions for the following routine). For a given value of r in (1:(n-1)), library(combinat) Set <- (1:n)

Howdy, I have done many searches and can't seem to find a way around this. I am reading in a .csv file where each row is a dataset and each column represents a position. The values are sparse (there are 2003 positions but usually only 100-200 values) and the idea is to be able to plot each dataset (row) and overlay them in different combinations. What I would like to do is have a plot

Greetings All. My apologies for a question whose answer is probably readily available somewhere (for some interpetation of "somewhere") ... Say I have just typed (from a sheet of paper) several lines into the R command-line, and what I see is: > chisq.test(matrix(c(3,6,3,4,4, + 4,1,4,6,5, + 2,7,4,2,5, + 8,2,4,4,2, +

AdvisoRs: Is the following a bug, feature, hinky error message, or dumb Bert? > mtest <- matrix(1:12,nr=4) > dftest <- data.frame(mtest) > ix <- cbind(1:2,2:3) > mtest[ix] <- NA > mtest [,1] [,2] [,3] [1,] 1 NA 9 [2,] 2 6 NA [3,] 3 7 11 [4,] 4 8 12 ## But ... > dftest[ix] <- NA Error in `[<-.data.frame`(`*tmp*`, ix, value

Hi all, all.equal is generally very useful when you want to find the differences between two objects. It breaks down however, when you have two long strings to compare: > all.equal(a, b) [1] "1 string mismatch" Does any one know of any good text diffing tools implemented in R? Thanks, Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice

Dear R-users, I have the following data x <- runif(300,min=1,max=230) y <- x*0.005 + 0.2 y <- y+rnorm(100,mean=0,sd=0.1) y <- y%%1 # <------- modulo operation plot(x,y) and would like to recapture the slope (0.005) and intercept(0.2). I wonder if there are any clever algorithms to do this. I was looking at the function lm.cirucalar. Is this the method to use? If, which of the

Greetings All. Once again, I am probably missing something fairly accessible, but since I can't find it I'd welcome advice! I have a dataframe derived from a text file of data in tabular format. For one of the variables, say X, I want to select the subsets which in which X equals a particular value. Such values are given in the text file like: 2.3978953, and each such value will occurr

Dear R-help, Could someone please try to explain this paradox to me? What is more likely to show up first in a string of coin tosses, "Heads then Tails", or "Heads then Heads"? ##generate 2500 strings of random coin flips ht <- replicate(2500, paste(sample(c("H", "T"), 100, replace = TRUE), collapse =

Hi Folks, The spreadsheet-like layout displayed when 'data.entry' is invoked is very useful simply for legible display of data, quite apart from its intended use for the purpose of entering or editing data. If one wants to use it _simply_ as a display device, so that one can look around inside a data-set while working on it, then it is not a good idea to have its _editing_ capabilities

Hi all, I?m working with a dataset with 9 columns and 2000 rows. Each row represents an individual and one of the columns represents the volume of that individual (measured in cubic meters). I?d like to select a sample from this dataset (without considering any probability of the rows) in which the sum of the volume of the individuals in that sample >= 100 cubic m. I?ll appreciate any

Hi, I have a function that approximates some data and indicates "segments". I'd like to plot the original data, and then the linear approximations on top of it. (Ideally, just a subset of N rows at a time, as the data set is large.) I can't figure out a clean way to do this. Suggestions? here is some sample data: ================================== Row X Seg ?.

Hi, Being a R-newbie I am wondering how to calculate a correlation coefficient (preferably with an associated p-value) for data like: > d[,1] [1] 25.5 25.3 25.1 NA 23.3 21.5 23.8 23.2 24.2 22.7 27.6 24.2 ... > d[,2] [1] 0.0 11.1 0.0 NA 0.0 10.1 10.6 9.5 0.0 57.9 0.0 0.0 ... Apparently corr(d) from the boot-library fails with NAs in the data, also cor.test cannot cope with a

Hi Folks, This tip is probably lurking somewhere already, but I've just discovered it the hard way, so it is probably worth passing on for the benefit of those who might otherwise hack their way along the same path. Say (for example) you want to do a logistic regression of a binary response Y on variables X1, X2, X3, X4: GLM <- glm(Y ~ X1 + X2 + X3 + X4) Say there are 1000 cases in the

I have a data file in which one of the columns is country code and NA is the code for Namibia. When I read the data file using read.csv, NA for Namibia is being treated as null or "NA" How can I prevent this from happening? I tried the following but it didn't work input <- read.csv("padded.csv",header = TRUE,as.is = c("code2")) thanks, Suresh [[alternative

Hi, How can I remove elements from a vector and them put them back in place?? An example (very simple, my vector/operations are much larger/complicated): Got a vector, lets say: a<-c(1,2,40,10,3,20,6); # I remove values larger than 10 a<-a[a<10] # Do some operations on the new a "1 2 3 6" b<-a^2 # Now b is "[1] 1 4 9 36" # Now I want to insert the elements I

A simple question - using the following fishers test it appears that the P value is significant, but the CI includes 1. Is this result correct? > data.50p10min <- matrix(c(16,15, 8, 24),nrow=2) > fisher.test(data.50p10min) Fisher's Exact Test for Count Data data: data.50p10min p-value = 0.03941 alternative hypothesis: true odds ratio is not equal to 1 95

Hi Ted and all, I have a couple of questions near the end of this message, but first I have to describe my problem in some detail. The power failure on Thursday did something evil to my ext3 file system (box running RH9+patches, ext3, /dev/md0, raid5 driver, 400GB f/s using 3x200GB IDE drives and one hot-spare). The f/s got corrupt badly and the symptoms are very similar to what Eddy described

Hello, R users, I have two factors (treat, section) anova design experiment where there are 3 replicates. The objective of the experiment is to test if there is significant difference of yield between top (section 9 to 11) and bottom (section 9 to 11) of the fruit tree under treatment. I found that there are interaction between two factors. I wonder if I can contrast means from levels of

Good morning once more. My problem of yesterday has been addressed. Having learned a few tricks from that, I wish to ask another question in connection with that. My data is a cosmic ray data consisting of dates and counts. When I plot a graph of counts versus dates, the resultant signal shows a number of maximum and minimum points. These minimum points (turning points) are of interest to me.

snat not working my local ip is aaa.aaa.aaa.aaa asterisk sitting on the internet at ip bbb.bbb.bbb.bbb my firewall''s internal ip is 192.168.0.254 i did snat: iptables -t nat -A POSTROUTING -o ppp0 -j SNAT --to aaa.aaa.aaa iptables -t nat -L -v gives: Chain POSTROUTING (policy ACCEPT 23663 packets, 2182K bytes) pkts bytes target prot opt in out source destination 33056