Hi Ramoss,
There are a few solutions to this - probably the best solution involves proper
handling of time series/date objects.
But, for "an" answer try:
# Build a data frame ...
set.seed(123)
someTimes <- sapply(1:5, function(i) sort(round(runif(6, 0, 24))))
myDf <- data.frame(Day = rep(1:5, each = 6), Hour = as.vector(someTimes))
# Do the lagging ...
do.call("rbind", lapply(split(myDf, myDf$Day), function(df) transform(df,
Lagged = c(NA, df$Hour[-nrow(df)]))))
Or you could use the "Lag" function (not the "lag" function) from Hmisc:
library(Hmisc)
set.seed(123)
someTimes <- sapply(1:5, function(i) sort(round(runif(6, 0, 24))))
myDf <- data.frame(Day = rep(1:5, each = 6), Hour = as.vector(someTimes))
# Do the lagging ...
do.call("rbind", lapply(split(myDf, myDf$Day), function(df) transform(df,
Lagged = Lag(df$Hour))))
kind regards,
---------------
Aga Matoga : amat...@mango-solutions.com<mailto:amat...@mango-solutions.com>
http://www.mango-solutions.com<http://www.mango-solutions.com/>, +44 (0)1249
705 450
--
LEGAL NOTICE\ \ This message is intended for the use of ...{{dropped:22}}
______________________________________________
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.
