Look again -- perhaps in your spam folder. Here's what he said:
" Reprex: dta <- read.table( text = "Yr Mo Dy Fuel 2021 7 25 50.45 2021 8 27 61.48 2021 9 26 59.07 2021 11 4 55.40 2021 11 22 30.63 2021 11 26 41.35 2021 12 6 32.81 2022 1 14 49.86 2022 4 29 62.99 2022 6 11 89.37 ", header=TRUE ) dta$Dtm <- with( dta, as.Date( ISOdate( Yr, Mo, Dy ) ) ) with( dta, plot( Dtm, Fuel ) ) The ISOdate function returns a POSIXct which includes time-of-day. Analyses that don't need time can instead rely on the Date type to avoid issues with timezones. " Bert Gunter On Wed, Jun 15, 2022 at 9:58 AM Gregory Coats via R-help <r-help@r-project.org> wrote: > > I do not see any posting on this topic from Jeff Newmiller. > I seek a way to “teach” R that "2021-07-25” represents a Year, Month, and Day. > Greg Coats > > > Fuel <- c(50.45, 61.48, 59.07, 55.40, 30.63, 41.35, 32.81, 49.86, 62.99, > > 89.37) > > plot (Fuel) > > Dates <- c("2021-07-25", "2021-08-27", "2021-09-26", "2021-11-04", > > "2021-11-22", "2021-11-26", "2021-12-06", "2022-01-14", "2022-04-29", > > "2022-06-11") > > plot (Dates) > Error in plot.window(...) : need finite 'ylim' values > In addition: Warning messages: > 1: In xy.coords(x, y, xlabel, ylabel, log) : NAs introduced by coercion > 2: In min(x) : no non-missing arguments to min; returning Inf > 3: In max(x) : no non-missing arguments to max; returning -Inf > > > xyplot (Dates, Fuel) > Error in xyplot(Dates, Fuel) : could not find function "xyplot" > > > On Jun 15, 2022, at 6:02 AM, Martin Maechler <maech...@stat.math.ethz.ch> > > wrote: > > Jeff Newmiller's answer which was much shorter *and* only > > used base R instead of an extra package > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.