gistfile1.r

# Plot correlation score in pairs() panel
panel.cor <- function(x, y, digits=2, prefix="", cex.cor)
{
  usr <- par("usr"); on.exit(par(usr))
  par(usr = c(0, 1, 0, 1))
  r = (cor(x, y, use="pairwise"))
  txt <- format(c(r, 0.123456789), digits=digits)[1]
  txt <- paste(prefix, txt, sep="")
  if(missing(cex.cor)) cex <- 0.6/strwidth(txt)
  text(0.5, 0.5, txt, cex=cex )
}

# Standard pairs using smoothed plots for large number of data points
pairs(data,
      upper.panel=function(...) smoothScatter(..., nrpoints=0, add=TRUE),
      lower.panel=panel.cor
      )