R + ggplot : Time series with events

Question

I\'m an R/ggplot newbie. I would like to create a geom_line plot of a continuous variable time series and then add a layer composed of events. The continuous variable and it

Answer 1

Plotly is an easy way to make ggplots interactive. To display events, coerce them into factors which can be displayed as an aesthetic, like color.

The end result is a plot that you can drag the cursor over. The plots display data of interest:

Here is the code for making the ggplot:

# load data    
data(presidential)
data(economics)

# events of interest
events <- presidential[-(1:3),]

# strip year from economics and events data frames
economics$year = as.numeric(format(economics$date, format = "%Y")) 

# use dplyr to summarise data by year
#install.packages("dplyr")
library(dplyr)
econonomics_mean <- economics %>% 
  group_by(year) %>% 
  summarise(mean_unemployment = mean(unemploy))

# add president terms to summarized data frame as a factor
president <- c(rep(NA,14), rep("Reagan", 8), rep("Bush", 4), rep("Clinton", 8), rep("Bush", 8), rep("Obama", 7))
econonomics_mean$president <- president

# create ggplot
p <- ggplot(data = econonomics_mean, aes(x = year, y = mean_unemployment)) +
  geom_point(aes(color = president)) +
  geom_line(alpha = 1/3)

It only takes one line of code to make the ggplot into a plotly object.

# make it interactive!
#install.packages("plotly")
library(plotly)
ggplotly(p)