similar to: r achives

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

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

hie how do you compute the logrank test using R what commands do you use my data looks something like just an example treatmentgrp strata censoringTime survivalTime censoring act.surv.time [1,] 2 2 42.89005 1847.3358 1 42.89005 [2,] 1 1 74.40379 440.3467 1 74.40379 [3,] 2 2

hie how do I specify the number of decuimal places for my calulations thanks __________________________________________________ [[alternative HTML version deleted]]

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

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

l'm trying to find the "survdiff" package/function but it seems i cant get it how do l instal it if its not there thanks --------------------------------- [[alternative HTML version deleted]]

hie l would like to create about ten strata l have tried using sample(c(1,2),1,replace=TRUE) but all l get is a vector of 1 and 2 if i change it to sample(c(1,10),1,replace=TRUE) it gives me a vector of 1 and 10 how do l go about it --------------------------------- [[alternative HTML version deleted]]

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)

hie when i use plot.survfit to plot more than one graph why I only see the last graph how do i see the other graphs.for example n=20 n1=n/2 n2=n/4 a11=4;a12=4 ;a21=4 ;a22=4 t1<-array(1,c(n1)) t2<-array(2,c(n1)) treatgrp=matrix(c(t1,t2))

I am trying to generate survival data using R .Im trying to randomly generate a column of 1s and 0 and another column randomly generated using an exponential distribution but l cant seem to get the random function. how do l go about it thanks in advance rt chiruka --------------------------------- [[alternative HTML version deleted]]

hie all i am trying to carry out a categorical data analysis but my problem is that when in i use the chi squared test some of my expected values are less than 5. is there a test that can handle this situation. the data is not a 2*2 table. its more from the social sciences where you have from strongly agree to strongly disagree. i know i can collapse vthe tables but there is a loss of

I just installed R on my 64 bit SUSE Linux system -- I compiled with the default x windows support on.. This may be a newbie question (apologies in advance)-- but how does this show up in X? I have SSH'd in to my box and set my display -- I can run xcalc OK -- but when I hit the R binary it just goes to the command line -- if does not give me an x-window. I suspect I need another

Hi, I would like to draw 10 uniformly distributed sample points from a circle with redius one and centered at (0,0). Is there any R function to do that?   Thanks, [[alternative HTML version deleted]]

in R when carring out the log rank test is the censored variable denoted by 1 or 0 or its of no consequence. thanks --------------------------------- always stay connected to friends. [[alternative HTML version deleted]]

hie is it possible to get the code for the logrank test l just need the chisquared value. thanks --------------------------------- [[alternative HTML version deleted]]

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

Hie I am trying to install Package DAAG this is the error I get > library(DAAG) Loading required package: randomForest Error: package 'randomForest' could not be loaded In addition: Warning message: In library(pkg, character.only = TRUE, logical.return = TRUE, lib.loc = lib.loc) : there is no package called 'randomForest' what should i do thanks The University of Fort Hare

Hi Folks, I'm wondering if there's a compact way to achieve the following. The "dream" is that, by analogy with rep(c(0,1),times=c(3,4)) # [1] 0 0 0 1 1 1 1 one could write rep(c(0,1),times=c(3,4,5,6)) which would produce # [1] 0 0 0 1 1 1 1 0 0 0 0 0 1 1 1 1 1 1 in effect "recycling" x through 'times'. The objective is to produce a vector of

Hi Folks, Maybe I've missed it already being available somehow, but if the following isn't available I'd like to suggest it. If you're happy to let plot() choose its own limits, then of course plot(x,y) will do it. If you know what limits you want, then plot(x,y,xlim=c(x0,x1),ylim(y0,y1) will do it. But sometimes one would like to a) make sure that (e.g.) the y-axis has a