similar to: Random number generator in R compared

l want to create a column of 1 and 2 randomly what command should l use eg treatment strata 1 1 2 0 1 1 2 1 2 0 2 1 2 0 1 0 these should be created randomly secondly if l have

i would like to add a variable to an existing matrix by manipulating 2 previous variables eg for the data m treat strata censti survTime [1,] 1 2 284.684074 690.4961005 [2,] 1 1 172.764515 32.3990335 [3,] 1 1 2393.195400 24.6145279 [4,] 2 1 30.364771 8.0272267 [5,] 1 1 523.182282 554.7659501 l

hie l would like to create a 6th column "actual surv time" from the following data the condition being if censoringTime>survivaltime then actual survtime =survival time else actual survtime =censoring time the code l used to create the data is s=2 while(s!=0){ n=20 m<-matrix(nrow=n,ncol=4)

I need to generate 100 I.I.D samples from an exponential distribution. I use rexp(100,parameter). Is there anyway to specify a seed to determine the first input for the uniform random number generator used to generate these exponentials? -Dhiren

dear list I use runif to generate a ramdom number between min and max runif(n, min=0, max=1) however , the syntaxe of rexp does not allow that rexp(n, rate = 1) and it generate a number with the corresponding rate. The question is: how to generate a number between min and max using rexp(). Regards -- PhD candidate in Computer Science Address 3 avenue lamine, cité ezzahra, Sousse 4000

how do l programme the logrank test. l am trying to compare 2 survival curves --------------------------------- [[alternative HTML version deleted]]

hie R users l have the following matrix n=20 m<-matrix(nrow=n,ncol=4) colnames(m)=c("treatmentgrp","strata","survivalTime") for(i in 1:n) m[i,]<-c(sample(c(1,2),1,replace=TRUE),sample(c(1:2),1,replace=TRUE),rexp(1,0.07),rexp(1,0.02))

Hi, I am trying to figure out the observed acceptance rate and M, using generalised rejection sampling to generate a sample from the posterior distribution for p. I have been told my code doesn't work because I need to "take the log of the expression for M, evaluate it and then exponentiate the result." This is because R is unable to calculate high powers such as 545.501. As

hie 1...i'm trying to carryout a relibility testusing cronbach's alpha what fuctin do i use. 2.. this is more of a statistical question.if the alpha value for all the variables is negative what does it mean. and if the alpha value is negative for all tyha variables but is greater than 0.7 for some sections of the variables what does that mean thanks in advance

Does anyone know if R have any problems with the exponential random number generation (function rexp)? I comment it because I executed data<-sort(rexp(100)) plot(data,dexp(data)/(1-pexp(data)),type="l") and the graphic isn't constant. (Note: exponential distribution have a constant hazard failure rate). Thank you, Juan

Maybe there is a great website out there or white paper that discusses this but again my Google skills (or lack there of) let me down. I would like to know the best way to export several doubles from a function, where the doubles are not an array. Here is a contrived function similar to my needs: multipleoutput<-function(x) { squared<-x^2 cubed<-x^3 exponentioal<-exp(x)

l would like to create the following matrice treatmentgrp strata 1 1 1 1 1 1 1 2 1 2 1 2 2 1 2 1 2 1 2 2 2 2 2 2 l should be able to choose the size of the treatment grps and stratas the method l used intially creates the

Dear Mr. for writing program about Gibbs sampling, i have a question. if i want to generate data from Exponential distribution but range of X is restricted, how can i do? regards, A.Rashidi   [[alternative HTML version deleted]]

Hi everyone! I'm trying to teach myself R in order to do some data analysis. I'm a mathematics student and (only) familiar with matlab and latex. I'm working trough the "official" introduction to R at the moment, while simultaneously solving some exercises I found in the web. Before I post my (probably stupid) question, I'd like to ask you for some general advice. How do

Say I have a dataframe like this: df <- data.frame(cbind(c(1,0,0,1),c(0,1,0,0),c(0,0,1,0))) names(df) <- c('a','b','c') I would like to create a factor in a new column, where the factor values are taken from the column names, like this: > df2 a b c f 1 1 0 0 a 2 0 1 0 b 3 0 0 1 c 4 1 0 0 a How would I do this? Thanks, Dan Daniel Nordlund Bothell, WA USA

I am using rexp to generate several exponential distributions. I am passing rexp a vector of rates , r. I am wanting to simulate a sample of size 200 for each rate so the code looks like: rexp(n=200*length(r),rate=r) this gives me a vector of the random exponential variables, but they are all disjointed b/c rexp goes through and simulates an exponential variable for each rate and it does that 200

If I have two matrices like x <- matrix(rep(c(1,2,3),3),3) y <- matrix(rep(c(4,5,6),3),3) How can I combine them to get ? 1 1 1 4 4 4 1 1 1 5 5 5 1 1 1 6 6 6 2 2 2 4 4 4 2 2 2 5 5 5 2 2 2 6 6 6 3 3 3 4 4 4 3 3 3 5 5 5 3 3 3 6 6 6 The number of rows and the actual numbers above are unimportant, they are given so as to illustrate how I want to combine the matrices. I.e., I am looking for

Hello, I wanted to ask help about importing sas datasets. 1)I tried with some functions as read.ssd (foreign package), but it doesn't import the file if the length of the variables' names are longer than 8 bite (it has to conform to the 6 version). 2)I then tried with the sas.get function (Hmisc package) but with the command: c<- sas.get(lib="c:\\ghan",

Any one know is there any package or function to generate bivariate exponential distribution? I gusee there should be three parameters, two rate parameters and one correlation parameter. I just did not find any function available on R. Any suggestion is appreciated. -- View this message in context:

Hello, I have written a function that demonstrates the CLT by generating samples following the exponential distribution, calculating the means, plotting the histogram, and drawing the limiting normal curve as an overlay. I have the title of each histogram state the sample size and rate (1/theta) for the exponential (the output is actually 4 histograms), but I can't get the greek letter theta