search for: totret

Hello Everyone, I just started a new job & it requires heavy use of R to analyze datasets. I have a data.table that looks like this. It is sorted by ID & Date, there are about 150 different IDs & the dataset spans 3 million rows. The main columns of concern are ID, date, and totret. What I need to do is to derive daily returns for each ID from totret, which is simply totret at time t+1 divided by totret at time t. X id ticker date_ adjClose totret RankStk 427225 427225 00174410 AHS 2001-11-13 21.66 100.00000 1235 441910 441910 001744...

Dear R Gurus, Thanks for any help in advance! Date.frame: Returns.names X id ticker date_ adjClose totret RankStk 258060 258060 13645T10 CP 2001-06-29 18.125 1877.758 My data frame is in the above format. I would like to filter by period, per id (every 125 days) each consisting of 250 days, I.e. 1-250, 126-375, etc. One important thing to note is that not all ID's have the same number...

Sample Data.Frame format Name is Returns.nodup X id ticker date_ adjClose totret RankStk 427225 427225 00174410 AHS 2001-11-13 21.66 100 1235 "id" uniquely defines a row What I am trying to do is filter out id's that have less than 1500 data points (by date) First, I used total<-by(Returns.nodup, Returns.nodup$id,nrow) which subsetted by ID a...