[R] General help on sample size based on recurrent events

Hello, I have a general help question that some of you might be able able to help. I would like to design a study (a two group comparison) based on reduction on events(say hospital admissions). In a previous study hospital admission rate of 140 admissions per 72 patients (over a 4 month period)

[R] General help on sample size based on recurrent events

Hello, I have a general help question that some of you might be able able to help. I would like calculate sample size for a study (a two group comparison) based on the outcome of reduction on (recurrent) events (say hospital admissions). In a previous study, hospital admission rate of 140 a

[R] sqldf with date (class date) variables ?

Hello, I am having trouble with retrieving some data in queries involve with variables with data type "date". See the enclosed example: ll<-c("21DEC2006","15DEC2006") ss<-data.frame(ll) ss<-transform(ss,ll=as.date(as.character(ll))) (ss) ll 1 17156 2 17150 tt<-sqldf("select ll from ss") (t

[R] Help, Statistics Question. Testing for equality of frequncies of an event

Hi All, I have a basic statistics question you might be able to help. I have some data collected within a single population (say of chronic illness) over a period of time (number under observation is constant, say 100 subjects). The question is how could I test whether the frequency of an even