On Fri, Jan 6, 2012 at 5:49 AM, <raphael.fel...@art.admin.ch> wrote: > Hello > > I have a data frame, called input, like this: > > DateTime CO2_A1cont > 1 2011-04-08 11:47:01 NA > 2 2011-04-08 12:42:01 8.90000 > 3 2011-04-08 13:07:01 NA > 4 2011-04-08 13:32:01 NA > 5 2011-04-08 13:57:01 7.556482 > 6 2011-04-08 14:22:01 NA > .... > 57 2011-04-09 16:52:01 4.961558 > > And like to plot this series with plot() and connected lines, no interruption > by the NAs. > I found that this code works: > > y<-input[,2] > times <- DateTime > > plot(y~as.POSIXct(times, format="%d.%m. %H:%M"), type="l", > data=na.omit(data.frame(y,times))) > > whereas this plot command... > > plot(input[,2]~as.POSIXct(DateTime, format="%d.%m. %H:%M"), type="l", > data=na.omit(data.frame(input[,2],DateTime))) > > ... produces the error: > > Error in model.frame.default(formula = input[, 2] ~ as.POSIXct(DateTime, : > variable lengths differ (found for 'as.POSIXct(DateTime, format = "%d.%m. > %H:%M")') > > I already checked the length of y, times, input[,2], DateTime, > as.POSIXct(DateTime, format="%d.%m. %H:%M") which give all 57! > nrow(data.frame(input[,2],DateTime)) and nrow(data.frame(y,times)) give both > 57! Too.
Try this reading DF into a zoo object. (tz="" has the effect of setting its index to POSIXct using the current time zone -- you might need tz = "GMT" depending on what you want): library(zoo) z <- read.zoo(DF, tz = "") plot(na.approx(z)) Assuming DF is: DF <- structure(list(DateTime = structure(1:6, .Label = c("2011-04-08 11:47:01", "2011-04-08 12:42:01", "2011-04-08 13:07:01", "2011-04-08 13:32:01", "2011-04-08 13:57:01", "2011-04-08 14:22:01"), class = "factor"), CO2_A1cont = c(NA, 8.9, NA, NA, 7.556482, NA)), .Names = c("DateTime", "CO2_A1cont"), class = "data.frame", row.names = c(NA, -6L)) -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ 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.