Try: cs <- with(txns,cumsum(cr - dr))
You could if needed adjust the starting value to zero by concatenating a zero in front and dropping the last entry. txns$running.bal <- c(0,cs[seq(length(cs) - 1)]) Good luck. seanpor wrote: > > Good morning, I've searched high and low and I've tried many different > ways > of doing this, but I can't seem to get it to work. > > I'm looking for a way of vectorising a "running balance"; i.e. the value > in > the first row of the dataframe is zero, and following rows add to this > running balance. This is easy to write in a loop, but I can't seem to get > it working in vectorised code. Hopefully the example below will explain > what I'm trying to do... > > Many thanks in advance, > > Best regards, > Sean O'Riordain > > -- View this message in context: http://www.nabble.com/running-balance-down-a-dataframe-referring-back-to-previous-row-tp16142263p16145133.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
