Question

I have a binary data set of 0 and 1, where 0 is an absence and 1 is a presence of an event.

A sample of the data set looks like this:

events    germany    Italy 
Rain      0          1
hail      1          0
sunny     0          0

I’d like to get a red and white picture of this data in the form of heat map by reading the data from a file.

Answer 1

With reshape and ggplot2 in R

library(reshape)
library(ggplot2)

dat <- data.frame(weather=c("Rain","Hail","Sunny"), Germany = c(0,1,0), Italy = c(1,0,0))

melt.data<-melt(dat, id.vars="weather", variable_name="country")

qplot(data=melt.data,
      x=country,
      y=weather,
      fill=factor(value),
      geom="tile")+scale_fill_manual(values=c("0"="white", "1"="red"))