| G_banking {lattice} | R Documentation |
Calculates banking slope
banking(dx, dy)
dx, dy |
vector of consecutive x, y differences. |
banking is the banking function used when
aspect = "xy" in high level Trellis functions. It is usually not
very meaningful except with xyplot. It considers the
absolute slopes (based on dx and dy) and returns a value
which when adjusted by the panel scale limits will make the median of
the above absolute slopes correspond to a 45 degree line.
This function was inspired by the discussion of banking in the
documentation for Trellis Graphics available at Bell Labs' website
(see Lattice), but is most likely identical to an
algorithm described by Cleveland et al (see below). It is
not clear (to the author) whether this is the algorithm used in
S-PLUS. Alternative banking rules, implemented as a similar function,
can be used as a drop-in replacement by suitably modifying
lattice.options("banking").
Deepayan Sarkar Deepayan.Sarkar@R-project.org
Cleveland, William S. and McGill, Marylyn E. and McGill, Robert (1988) “The Shape Parameter of a Two-variable Graph”, Journal of the American Statistical Association, 83, 289–300.
## with and without banking
plot <- xyplot(sunspot.year ~ 1700:1988, xlab = "", type = "l",
scales = list(x = list(alternating = 2)),
main = "Yearly Sunspots")
print(plot, position = c(0, .3, 1, .9), more = TRUE)
print(update(plot, aspect = "xy", main = "", xlab = "Year"),
position = c(0, 0, 1, .3))
## cut-and-stack plot (see also xyplot.ts)
xyplot(sunspot.year ~ time(sunspot.year) | equal.count(time(sunspot.year)),
xlab = "", type = "l", aspect = "xy", strip = FALSE,
scales = list(x = list(alternating = 2, relation = "sliced")),
as.table = TRUE, main = "Yearly Sunspots")