Using lubridate and ggplot2 is effective for date axis

Question

Consider the following example:

library(ggplot2) library(lubridate) set.seed(4) date <- seq(from = as.POSIXct("2012-01-01"), to = as.POSIXct("2014-12-31"), by = "days") value <- c(rnorm(274, 50, 1), rnorm(274, 55, 1), rnorm(274, 55, 2), rnorm(274, 60, 2)) df <- data.frame(date, value) head(df) # date value # 1 2012-01-01 50.21675 # 2 2012-01-02 49.45751 # 3 2012-01-03 50.89114 # 4 2012-01-04 50.59598 # 5 2012-01-05 51.63562 # 6 2012-01-06 50.68928 ggplot(df, aes(x=yday(date), y=value, color=factor(year(date)))) + geom_line() 

What generates this graph:

What are some ways to make an axis formatted as date by month? I am trying to define a clean way to use both lubridate and scale_x_date , if possible?

Perhaps there are better ways to create this type of graph? That is, creating factors over the years and laying them on top of each other? (NOTE: I do not want to use facet_wrap or facet_grid for this example).

Answer 1

One solution would be to add a column to your data framework that will contain day and month for each row in another year (the same for all rows), for example, 2015.

 df$days<-as.Date(format(df$date,"%d-%m-2015"),format="%d-%m-%y") 

Then you can use this column as x

 library(scales) ggplot(df, aes(x=days, y=value, color=factor(year(date)))) + geom_line()+scale_x_date(labels = date_format("%b")) 

Edit: simplified df$days