ca (version 0.72)

multilines: Draw lines for groups distinguished by a factor

Description

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.

Usage

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

Value

none

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

Author

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)
}