Hauck-Donner Effects: Segmented Lines Plot
Plots the piecewise segmented curve made up of Wald statistics versus estimates, using a colour code for the HDE severity.
seglines(x, y, dy, ddy, lwd = 2, cex = 2, plot.it = TRUE,
add.legend = TRUE, position.legend = "topleft",
lty.table = c("solid", "dashed", "solid", "dashed",
"solid", "dashed", "solid"),
col.table = rainbow.sky[-5], pch.table = 7:1,
severity.table = c("None", "Faint", "Weak",
"Moderate", "Strong", "Extreme", "Undetermined"),
tol0 = 0.1, FYI = FALSE, ...)x, y, dy, ddy |
Same as |
lwd, cex |
Graphical parameters: line width, and character expansion. |
plot.it |
Logical, plot it? If |
add.legend, position.legend |
Logical and character; add a legend?
The other argument is fed into |
severity.table, tol0 |
Same as |
lty.table, col.table, pch.table |
Graphical parameters for the 7 different types of segments. Usually users should not assign anything to these arguments. |
FYI, ... |
Should be ignored. |
This function was written to complement hdeffsev
and is rough-and-ready.
It plots the Wald statistics as a function of
the estimates, and uses a colour-code to indicate
the severity of the
Hauck-Donner effect (HDE).
This can be obtained from its first two derivatives.
This function returns the severity of the HDE, possibly invisibly.
This function is likely to change in the short future because it is experimental and far from complete.
Thomas W. Yee.
deg <- 4 # myfun is a function that approximates the HDE
myfun <- function(x, deriv = 0) switch(as.character(deriv),
'0' = x^deg * exp(-x),
'1' = (deg * x^(deg-1) - x^deg) * exp(-x),
'2' = (deg * (deg-1) * x^(deg-2) - 2*deg * x^(deg-1) + x^deg) * exp(-x))
## Not run:
curve(myfun, 0, 10, col = "white")
xgrid <- seq(0, 10, length = 101)
seglines(xgrid, myfun(xgrid), myfun(xgrid, deriv = 1),
myfun(xgrid, deriv = 2), position = "bottom")
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.