visualizaztion explorer

library(ggplot2)
library(gridExtra)

create a dataset

xvar <- c(rnorm(1500, mean = -1), rnorm(1500, mean = 1.5))
yvar <- c(rnorm(1500, mean = 1), rnorm(1500, mean = 1.5))
zvar <- as.factor(c(rep(1, 1500), rep(2, 1500)))
xy <- data.frame(xvar, yvar, zvar)

a couple of histogram plots

g1<-ggplot(xy, aes(xvar))+geom_histogram() # horribly ugly default
g2<-ggplot(xy, aes(xvar))+geom_histogram(binwidth=1) #change binwidth
g3<-ggplot(xy, aes(xvar))+geom_histogram(fill=NA,color="black")+theme_bw() #nicer looking
#density on y-axis
g4<-ggplot(xy, aes(x=xvar))+geom_histogram(aes(y=..density..), color="black", fill=NA)+theme_bw()
grid.arrange(g1,g2,g3,g4, nrow=1)

density plots

p1<-ggplot(xy, aes(xvar))+geom_density()
#hist and densityline overlaid
p2<-ggplot(xy,aes(x=xvar))+geom_histogram(aes(y=..density..), color="black", fill=NA)+geom_density(color="blue")
#split and color by third variable, alpha fades the color a bit
p3<-ggplot(xy, aes(xvar, fill=zvar))+geom_density(alpha=0.2)
grid.arrange(p1,p2,p3,nrow=1)

boxplot, jitter plot, violin plot

rug plot

ggplot(xy, aes(xvar, yvar))+geom_point()+geom_rug(col="darkred", alpha=.1)

add histogram, density plots