running balance down a dataframe referring back to previous row
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
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