Mark a point null hypothesis in an HE plot

A utility function to draw and label a point in a 2D (or 3D) HE plot corresponding to a point null hypothesis being tested. This is most useful for repeated measure designs where null hypotheses for within-S effects often correspond to (0,0).

Usage

mark.H0(
  x = 0,
  y = 0,
  z = NULL,
  label,
  cex = 2,
  pch = 19,
  col = "green3",
  lty = 2,
  pos = 2
)

Arguments

x: Horizontal coordinate for H0
y: Vertical coordinate for H0
z: z coordinate for H0. If not NULL, the function assumes that a heplot3d plot has been drawn.
label: Text used to label the point. Defaults to expression(H[0]) in 2D plots.
cex: Point and text size. For 3D plots, the function uses size=5*cex in a call to points3d.
pch: Plot character. Ignored for 3D plots.
col: Color for text, character and lines
lty: Line type for vertical and horizontal reference lines. Not drawn if lty=0.
pos: Position of text. Ignored for 3D plots

Value

None. Used for side effect of drawing on the current plot.

Author

Michael Friendly

Examples


Vocab.mod <- lm(cbind(grade8,grade9,grade10,grade11) ~ 1, data=VocabGrowth)
idata <-data.frame(grade=ordered(8:11))

heplot(Vocab.mod, type="III", idata=idata, idesign=~grade, iterm="grade",
  main="HE plot for Grade effect")
mark.H0()