RG#54: Scatter Diagram with Rugs, Spike Histogram, or Density

# data 

set(123)

x <- rnorm(1000, 50, 30)

y <- 3*x + rnorm(1000, 0, 20)

require(Hmisc)

plot(x,y)

#scat1d adds tick marks (bar codes. rug plot) 

# on any of the four sides of an existing plot, 

# corresponding with non-missing values of a vector x.

scat1d(x, col = "red")                 # density bars on top of graph

scat1d(y, 4, col = "blue")              # density bars at right

plot(x,y, pch = 19)

histSpike(x, add=TRUE, col = "green4", lwd = 2)       

histSpike(y, 4, add=TRUE,col = "blue", lwd = 2 )

histSpike(x, type='density',col = "red", add=TRUE)  # smooth density at bottom

histSpike(y, 4, type='density', col = "red", add=TRUE)

plot(x,y, pch = 19)

smooth <- lowess(x, y)    # add nonparametric regression curve
lines(smooth, col = "red")             # Note: plsmo() does this

scat1d(x, y=approx(smooth, xout=x)$y, col = "yellow") # data density on curve

scat1d(x, curve=smooth, col = "yellow")   # same effect as previous command

# data 
set(123)
x <- rnorm(1000, 50, 30)
y <- 3*x + rnorm(1000, 0, 60)

plot(x,y, pch = 19, col = "cyan3")

histSpike(x, curve=smooth, add=TRUE, col = "yellow") # same as previous but with histogram
histSpike(x, curve=smooth, type='density', col = "red",lwd=2, add=TRUE)