Script help: Determining Time Difference between two data points.
Look at ?as.numeric.difftime > z <- f(d, d$Score > 150) > elapsedTime <- z$endDate - z$startDate > units(elapsedTime) [1] "secs" > as.numeric(elapsedTime, units="hours") [1] 7.616667 0.000000 192.700000 4.366667 62.966667 0.000000 12.500000 0.000000 > as.numeric(elapsedTime, units="days") [1] 0.3173611 0.0000000 8.0291667 0.1819444 2.6236111 0.0000000 0.5208333 0.0000000 > as.numeric(elapsedTime, units="secs") [1] 27420 0 693720 15720 226680 0 45000 0 Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com
-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of APOCooter Sent: Tuesday, July 17, 2012 11:41 AM To: r-help at r-project.org Subject: Re: [R] Script help: Determining Time Difference between two data points. Yes! That does exactly what I want it to. Thank you so much. One question, though, is it possible that the time difference be in hours instead of seconds (other than dividing by 3600)? Looking at the code, I don't know what I would change. Does this do what you want?
> firstInRun <- function(x) c(TRUE, x[-1] != x[-length(x)])
> lastInRun <- function(x) c(x[-1] != x[-length(x)], TRUE)
> f <- function(data, condition) {
+ with(data, data.frame(startDate = Date[firstInRun(condition)], + endDate = Date[lastInRun(condition)])) + }
> f(d, d$Score > 150)
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