search for: jymint

Hi everyone, I am not new to R, but its been over a year since I've used it, so I don't remember how to do some things. I have a data set (in excel currently, but will be converted to text), that has date, country and price, with a price for every country for every date. I need to find the mean and median of the interval between price changes for each country and the mean and median

...frame(country=rep(c("au","br""cn","in","us"),each=100), date=rep(as.Date("02/02/2008", format="%d/%m/%Y"),500)+sample(-40:40,500,TRUE), price=rnorm(500,100,20)) # get the intervals by country - have to create a new data frame jymint.df<-data.frame(country=rep(levels(jym.df$country),each=99), intervals=unlist(tapply(jym.df$date,jym.df$country,diff))) library(prettyR) # break down the intervals by country brkdn(intervals~country,jymint.df,num.desc=c("mean","median")) But, obviously the first step generat...