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

Now I like ggplot as much as the next guy, but if you want to make the Google Finance type charts, why not just do it with the Google graphics API?!? You're going to love this:

install.packages("googleVis")
library(googleVis)

dates <- seq(as.Date("2011/1/1"), as.Date("2011/12/31"), "days")
happiness <- rnorm(365)^ 2
happiness[333:365] <- happiness[333:365]  * 3 + 20
Title <- NA
Annotation <- NA
df <- data.frame(dates, happiness, Title, Annotation)
df$Title[333] <- "Discovers Google Viz"
df$Annotation[333] <- "Google Viz API interface by Markus Gesmann causes acute increases in happiness."

### Everything above here is just for making up data ### 
## from here down is the actual graphics bits        ###
AnnoTimeLine  <- gvisAnnotatedTimeLine(df, datevar="dates",
                                       numvar="happiness", 
                                       titlevar="Title", annotationvar="Annotation",
                                       options=list(displayAnnotations=TRUE,
                                                    legendPosition='newRow',
                                                    width=600, height=300)
                                       )
# Display chart
plot(AnnoTimeLine) 
# Create Google Gadget
cat(createGoogleGadget(AnnoTimeLine), file="annotimeline.xml")

and it produces this fantastic chart: