[R] getting the value from previous row

[Milan Bouchet-Valat]

Le vendredi 13 avril 2012 à 06:09 -0700, arunkumar1111 a écrit :
> Hi
> 
> I've a dataset  with record  A  = 100,200,300,400...
> 
> There will be a parameter n.  say n=10 means i have add 10% of previous
> value to the current row
> 
> current_Val New_value
> 100                   100
> 200                    210 (200+10)
> 300                    330( 300 +20+10)
> 400                     460 (400+30+20+10)
> 
> I'm using a loop
> But i want takes a long time. Please help
One solution is:
A <- 1:4 * 100
A + cumsum(c(0, A[-length(A)]) * 0.1)
[1] 100 210 330 460


Hope this helps