X-axis graph rotate labels in R

Question

I have to build this data:

day temperature 02/01/2012 13:30:00 10 10/01/2012 20:30:00 8 15/01/2012 13:30:00 12 25/01/2012 20:30:00 6 02/02/2012 13:30:00 5 10/02/2012 20:30:00 3 15/02/2012 13:30:00 6 25/02/2012 20:30:00 -1 02/03/2012 13:30:00 4 10/03/2012 20:30:00 -2 15/03/2012 13:30:00 7 25/03/2012 20:30:00 1 

on the x axis, I want to mark only the month and day (for example, January 02), rotating 45 degrees. How to do this using the plot () command?

Answer 1

Using basic graphics:

 tab <- read.table(textConnection(' "02/01/2012 13:30:00" 10 "10/01/2012 20:30:00" 8 "15/01/2012 13:30:00" 12 "25/01/2012 20:30:00" 6 "02/02/2012 13:30:00" 5 "10/02/2012 20:30:00" 3 "15/02/2012 13:30:00" 6 "25/02/2012 20:30:00" -1 "02/03/2012 13:30:00" 4 "10/03/2012 20:30:00" -2 "15/03/2012 13:30:00" 7 "25/03/2012 20:30:00" 1')) tab[, 1] <- as.POSIXct(tab[, 1], format = "%d/%m/%Y %H:%M:%S") plot(V2 ~ V1, data=tab, xaxt="n") tck <- axis(1, labels=FALSE) labels <- format(as.POSIXct(tck, origin="1970-01-01"), "%b %d") text(tck, par("usr")[3], labels=labels, srt=315, xpd=TRUE, adj=c(-0.2,1.2), cex=0.9) 

Answer 2

with ggplot :

 tab <- read.table(textConnection(" 02/01/2012 13:30:00 10 10/01/2012 20:30:00 8 15/01/2012 13:30:00 12 25/01/2012 20:30:00 6 02/02/2012 13:30:00 5 10/02/2012 20:30:00 3 15/02/2012 13:30:00 6 25/02/2012 20:30:00 -1 02/03/2012 13:30:00 4 10/03/2012 20:30:00 -2 15/03/2012 13:30:00 7 25/03/2012 20:30:00 1")) tab[, 1] <- as.Date(tab[, 1], format = "%d/%m/%Y") library(ggplot2) ggplot(tab) + geom_point(aes(x = V1, y = V3)) + theme(axis.text.x = element_text(angle = 45, hjust = 1))