Thank you. I�ll see what I can do with that. From: Rui Barradas <ruipbarra...@sapo.pt> Date: Monday, September 19, 2022 at 1:28 PM To: Parkhurst, David <parkh...@indiana.edu>, r-help@r-project.org <r-help@r-project.org> Subject: Re: [R] Converting time format Hello,
I will run the examples below with the following data: x <- c("12:00", "12:15", "12:30", "12:45", "13:00", "13:15", "13:30", "13:45", "14:00", "14:15", "14:30", "14:45", "15:00", "15:15", "15:30", "15:45", "16:00", "16:15", "16:30", "16:45", "17:00", "17:15", "17:30", "17:45", "18:00") b <- data.frame(time = x, myvar = sin(2*pi*seq_along(x)/length(x))) Are they are saying is true, the vector b$myvar is a character vector and that's what is being displayed. In what follows I will first give examples of base graphics. The times are first coerced to a proper time class with package chron. library(chron) b$time <- as.times(b$time) # see ?plot.default for the meaning of # argument 'type' plot(myvar ~ time, b) plot(myvar ~ time, b, type = "l") plot(myvar ~ time, b, type = "b") With ggplot2, there is no need to load a date/time class package, R can do it with ?as.POSXct but the labels are datetime_breaks and datetime_labels. library(ggplot2) b |> dplyr::mutate(time = paste(Sys.Date(), time), time = as.POSIXct(time)) |> ggplot(aes(time, myvar)) + geom_line() + geom_point() + scale_x_datetime(date_breaks = "1 hour", date_labels = "%H:%M") + theme_bw() Hope this helps, Rui Barradas �s 01:56 de 19/09/2022, Parkhurst, David escreveu: > I have a dataframe obtained using read.csv from an excel file. Its first > column is times, running from 18:00 to 19:30. If I want to plot other > columns against time, do I need to convert those somehow, and how would I do > that? > > If I run plot(b$time,b$myvar) I get a decent plot, but a friend suggests that > R is just treating those numbers as text, and putting them in alphabetical > order. True? > > [[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. [[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.