multilines function

Draw lines for groups distinguished by a factor

This is a convenience function for drawing a set of lines distinguished by the levels of a factor. It can be used to make more attractive plots than available via plot.mjca.

multilines(XY, group=NULL, which=1:nf, sort=1, type='l', col=palette(), lwd=1, ...)

Arguments

• XY: A two-column data frame or matrix
• group: A factor; a separate line is drawn for each level included in which
• which: An integer vector used to select the factors for which lines are drawn. By default, all lines are drawn.
• sort: Column of XY to sort upon before drawing the line for each group
• type: Line type: "l" for line, "b" for line and points
• col: A vector of colors to be used for the various lines, in the order of the levels in group; recycled as necessary.
• lwd: A vector of line widths to be used for the various lines; recycled as necessary
• ...: Other graphic parameters passed to lines, e.g., lty

Returns

none

Author(s)

Michael Friendly

See Also

lines

Examples

if (require(vcd)) {
  data(PreSex, package="vcd")
  presex.mca <- mjca(PreSex)
  res <- plot(presex.mca, labels=0, pch='.', cex.lab=1.2)
  coords <- data.frame(res$cols, presex.mca$factors)      
  nlev <- rle(as.character(coords$factor))$lengths
  fact <- unique(as.character(coords$factor))
  
  cols <- c("blue", "red", "brown", "black")
  lwd <- c(2, 2, 2, 4)
  
  plot(Dim2 ~ Dim1, type='n', data=coords)
  points(coords[,1:2], pch=rep(16:19, nlev), col=rep(cols, nlev), cex=1.2)
  text(coords[,1:2], labels=coords$level, col=rep(cols, nlev), pos=3, cex=1.2, xpd=TRUE)
  
  multilines(coords[, c("Dim1", "Dim2")], group=coords$factor, col=cols, lwd=lwd)
}