search for: chisqr

l used the following code to generate a sample and then calculated then did a log rank test.can l get the normal version of the logrank eg sqrt of the chisqr(1) will give you the N~(0,1). from my sample can i use the above expression to get the normal dist from the result of the log rank test. thank s=1 while(s!=0){ n=100 m<-matrix(nrow=n,ncol=4) colnames(m)=c("treatmentgrp","strata","cen...

...ad data using foreign package - must be Stata 11 or earlier racedata<- read.dta("race.dta")??? # item responses resp.data<-racedata[,-c(1:2)] # grouping variable is in the second column af<-racedata[,2] # run lordif >race.dif<-lordif(resp.data, af, criterion="Chisqr", alpha=0.05, minCell=1) >attributes(race.dif) >ipar1 <- race.dif$ipar > class(ipar1) [1] "data.frame" > class(resp.data) [1] "data.frame" > head(ipar1) ????????? a????? cb1 I1 2.565834 1.959045 I2 2.033049 1.389847 I3 2.693962 1.951471 I4 1.7...

...lecting a set of words or word combinations which have better discriminant capability than other words in telling the group id's (2 classes in this case) for a dataset which has 2,000,000 documents. One approach is using "contrast-set association rule mining" while the other is using chisqr or fisher exact test. An example which has 3 contingency tables for 3 words as followed (word coded by number): > tab[,,1:3] , , 1 [,1] [,2] [1,] 11266 2151526 [2,] 125 31734 , , 2 [,1] [,2] [1,] 43571 2119221 [2,] 52 31807 , , 3 [,1] [,2] [1,] 427 21623...