R/pairsPanels.R

In Sz-Tim/sevcheck: It's pronounced 'sev-check'

#' creates histograms for \code{\link{pairs}}
#' 
#' This function is from the help file for \code{\link{pairs}}. It generates a 
#' histogram to be used in the panels instead of the default scatterplot. This
#' works best on the diagonal (panel.diag=panel.hist).
#' 
#' @export 

panel.hist <- function(x, ...)
{
  usr <- par("usr"); on.exit(par(usr))
  par(usr = c(usr[1:2], 0, 1.5) )
  h <- hist(x, plot = FALSE)
  breaks <- h$breaks; nB <- length(breaks)
  y <- h$counts; y <- y/max(y)
  rect(breaks[-nB], 0, breaks[-1], y, col = "cyan", ...)
}





#' calculates correlations for \code{\link{pairs}}
#' 
#' This function is from the help file for \code{\link{pairs}}. It calculates 
#' correlation coefficients to be used in the panels instead of the default 
#' scatterplot. The font size is scaled. (panel.upper=panel.hist).
#' 
#' @export
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 <- abs(cor(x, y))
  txt <- format(c(r, 0.123456789), digits = digits)[1]
  txt <- paste0(prefix, txt)
  if(missing(cex.cor)) cex.cor <- 0.8/strwidth(txt)
  text(0.5, 0.5, txt, cex = cex.cor * r)
}