Fig7.1n <- function()
{
#  postscript(file = "Fig7.1.ps", height = 6.5, width = 6.5, horiz = F)
  par(mfrow = c(2, 2), mar = c(1.5, 1.5, 1.5, 0.5), mgp = c(5, 0.4, 0))
  x <- seq(-3.3, 3.3, length = 512)
  y <- sapply(x, fff)
  ywd <- wd(y, filter.number = 10)
  ywd1 <- ywd
  ywd2 <- ywd
  ywd3 <- ywd
  ywd4 <- ywd
  coefvals <- rev(sort(abs(ywd$D)))
  ywd1$D <- ywd$D * (abs(ywd$D) >= coefvals[3])
  ywd2$D <- ywd$D * (abs(ywd$D) >= coefvals[7])
  ywd3$D <- ywd$D * (abs(ywd$D) >= coefvals[11])
  ywd4$D <- ywd$D * (abs(ywd$D) >= coefvals[15])
  plot(x, wr(ywd1), type = "l", xlab = "", ylab = "")
  mtext("4 coefficients", side = 3, line = 0.1)
  plot(x, wr(ywd2), type = "l", xlab = "", ylab = "")
  mtext("8 coefficients", side = 3, line = 0.1)
  plot(x, wr(ywd3), type = "l", xlab = "", ylab = "")
  mtext("12 coefficients", side = 3, line = 0.1)
  plot(x, wr(ywd4), type = "l", xlab = "", ylab = "")
  mtext("16 coefficients", side = 3, line = 0.1)
#  graphics.off()
  NULL
}