You need to specify what the format of the date will be. I am using ggplot for the plot:
library(lubridate) library(tidyverse) mydata <- read.table(text = "time value 20181028_10:00:00 600 20181028_10:00:01 500 20181028_10:00:02 450 20181028_10:00:03 660", header = TRUE, as.is = TRUE) mydata <- mutate(mydata, time = ymd_hms(time) ) ggplot(mydata, aes(time, value)) + geom_point() + scale_x_datetime(date_labels = "%m/%d %H:%M:%S" ) + theme(axis.text.x = element_text(angle = 25, vjust = 1.0, hjust = 1.0)) Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. On Sun, Oct 28, 2018 at 11:23 AM snowball0916 <snowball0...@163.com> wrote: > > Hi, guys > How do you guys deal with the date and time data on x axis? > I have some trouble with it. Could you help with this? > > ============= > Sample Data > ============= > The sample data look like this: > > 20181028_10:00:00 600 > 20181028_10:00:01 500 > 20181028_10:00:02 450 > 20181028_10:00:03 660 > ...... > > ============= > My Code > ============= > > library(lubridate) > mydata <- read.table("e:/R_study/graph_test2.txt") > xdata <- ymd_hms(mydata$V1) > ydata <- mydata$V2 > plot(xdata, ydata, type="o") > > > ============= > Questions: > ============= > > 1. Why my x axis does not show me the correct date time like ""2018-10-28 > 10:00:00 UTC" ? > 2. If my data is very huge(like data in every second and the data has the > whole day , even the whole month), how can I display the x axis in a neat and > clean way? > > Thanks very much. > > > > > [[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.