Correlation matrix plot with ggplot2

Question

I want to create a correlation matrix plot, i.e. a plot where each variable is plotted in a scatterplot against each other variable like with pairs() or s

Answer 1

library(GGally)

set.seed(42)
d = data.frame(x1=rnorm(100),
               x2=rnorm(100),
               x3=rnorm(100),
               x4=rnorm(100),
               x5=rnorm(100))

# estimated density in diagonal
ggpairs(d)

# blank
ggpairs(d, diag = list("continuous"="blank")

Answer 2

Using PerformanceAnalytics library :

library("PerformanceAnalytics")
chart.Correlation(df, histogram = T, pch= 19)