Differenced Zeta Distribution
Density, distribution function, quantile function, and random generation for the differenced zeta distribution.
ddiffzeta(x, shape, start = 1, log = FALSE) pdiffzeta(q, shape, start = 1, lower.tail = TRUE) qdiffzeta(p, shape, start = 1) rdiffzeta(n, shape, start = 1)
This distribution appears to work well on the distribution
of English words in such texts.
Some more details are given in diffzeta.
ddiffzeta gives the density,
pdiffzeta gives the distribution function,
qdiffzeta gives the quantile function, and
rdiffzeta generates random deviates.
Given some response data, the VGAM family function
diffzeta estimates the parameter shape.
Function pdiffzeta() suffers from the problems that
plog sometimes has, i.e., when p
is very close to 1.
T. W. Yee
ddiffzeta(1:20, 0.5, start = 2)
rdiffzeta(20, 0.5)
## Not run: shape <- 0.8; x <- 1:10
plot(x, ddiffzeta(x, shape = shape), type = "h", ylim = 0:1,
sub = "shape=0.8", las = 1, col = "blue", ylab = "Probability",
main = "Differenced zeta distribution: blue=PMF; orange=CDF")
lines(x + 0.1, pdiffzeta(x, shape = shape), col = "orange", lty = 3, type = "h")
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.