I added a zero initial entry to the data set. Greg gcdf<-read.table(text="2013-11-29 00.000 2013-12-29 19.175 2014-01-20 10.072 2014-02-12 10.241 2014-03-02 05.916
> On Dec 16, 2020, at 12:32 PM, Gregory Coats via R-help <r-help@r-project.org> > wrote: > > Jim, Thank you! > The data set begins > gcdf<-read.table(text="2013-12-29 19.175 > 2014-01-20 10.072 > 2014-02-12 10.241 > I note that data begins in 2013. But the plot command does not show this > first entry in 2013, and instead shows the second data pair as the first data > pair. As a consequence, plot does not show the first data pair for 2013, and > begins in 2014. > Greg > >> On Dec 16, 2020, at 1:08 AM, Jim Lemon <drjimle...@gmail.com> wrote: >> >> Hi Greg, >> I think this does what you want: >> >> gcdf$date<-as.Date(gcdf$date,"%Y-%m-%d") >> grid_dates<-as.Date(paste(2014:2020,1,1,sep="-"),"%Y-%m-%d") >> plot(gcdf$date, gcdf$gallons, main="2014 Toyota 4Runner", xlab="Date", >> ylab="Gallons",type="l",col="blue",yaxt="n") >> abline(h=seq(4,20,by=2),lty=4) >> abline(v=grid_dates,lty=4) >> axis(side=2,at=seq(4,20,by=2)) >> >> Jim >> >> On Wed, Dec 16, 2020 at 2:16 PM Gregory Coats <gregco...@me.com> wrote: >>> >>> Jim, Thanks for your help with R. >>> Feeding into R the file R_plot_18.r yields for me, on my Mac, >>> R_plot_18.pdf. Success. >>> I used abline to draw a horizontal background grid, and then used axis >>> label to identify the values represented by the horizontal dashed >>> background lines. >>> abline (h=c(2,4,6,8,10,12,14,16,18,20,22,24), lty=4, lwd=1.0, col="grey60") >>> Similarly, I would like to draw a dashed vertical background grid. But it >>> is unclear to me how to direct R to draw a vertical dashed background grid >>> because I am again baffled how to specify to R a date value such as >>> 2018-10-20 @18:00. I welcome your guidance. >>> Greg >>> >>> On Dec 13, 2020, at 10:58 PM, Jim Lemon <drjimle...@gmail.com> wrote: >>> >>> Hi Gregory, >>> >>> On Mon, Dec 14, 2020 at 12:34 PM Gregory Coats <gregco...@me.com> wrote: >>> >>> ... >>> Is there a convenient way to tell R to interpret “2020-12-13” as a date? >>> >>> Notice the as.Date command in the code I sent to you. this converts a >>> string to a date with a resolution of one day. If you want a higher >>> time resolution, use strptime or one of the other POSIX date >>> conversion functions. >>> >>> Jim ______________________________________________ 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.
