Try this: > Lines <- "19:21:59.855 + 19:21:59.905 + 19:21:59.955 + 19:22:0.5 + 19:22:0.55 + 19:22:0.105 + 19:22:0.155 + 19:22:0.205 + 19:22:0.255 + 19:22:0.305 + 19:22:0.355 + 19:22:0.405" > > DF <- read.table(textConnection(Lines)) > library(chron) > tt <- times(DF[[1]]) > diff(tt) [1] 5.787037e-07 5.787037e-07 6.307870e-06 5.787037e-07 -5.150463e-06 [6] 5.787037e-07 5.787037e-07 5.787037e-07 5.787037e-07 5.787037e-07 [11] 5.787037e-07
On Thu, Jul 16, 2009 at 11:18 AM, Dave Deriso<dder...@ucsd.edu> wrote: > Hello, > > I have been attempting to write a script that automatically calculates time > intervals from a list of hh.mm.ss.ms timestamps. Should be easy, but I keep > running into problems. Any help would be greatly appreciated!! > > Problems: > 1. If I parse the timestamp, it doesn't always return the digits after the > decimal > 2. If I subtract .5 - .955 (as in 19:22:0.5 - 19:21:59.955), then I get a > really big negative number > > Here is sample data: > > 19:21:59.855 > 19:21:59.905 > 19:21:59.955 > 19:22:0.5 > 19:22:0.55 > 19:22:0.105 > 19:22:0.155 > 19:22:0.205 > 19:22:0.255 > 19:22:0.305 > 19:22:0.355 > 19:22:0.405 > > Here is my code: > > #attempts to parse milliseconds from timestamp > for (i in 1:200){k[i] = > rbind(substring(TimeStamp[i,3],8:10)[which(substring(TimeStamp[i,3],8:10)<1)])} > > #attempts to intelligently subtract intervals > for (i in 1:200){if(as.numeric(k[(i+1)])>as.numeric(k[(i)])){k2[i] = > rbind(as.numeric(k[(i+1)])-as.numeric(k[(i)]))}else{k2[i] = > rbind((1+as.numeric(k[(i+1)]))-as.numeric(k[(i)]))}} > > Thanks so much for your help!!! > > Best, > > Dave Deriso > UCSD Psychiatry > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > ______________________________________________ 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.