ggammaUC {VGAM} | R Documentation |
Density, distribution function, quantile function and random
generation for the generalized gamma distribution with
scale parameter scale
,
and parameters d
and k
.
dggamma(x, scale=1, d=1, k=1) pggamma(q, scale=1, d=1, k=1) qggamma(p, scale=1, d=1, k=1) rggamma(n, scale=1, d=1, k=1)
x, q |
vector of quantiles. |
p |
vector of probabilities. |
n |
number of observations. Positive integer of length 1. |
scale |
the (positive) scale parameter b. |
d, k |
the (positive) parameters d and k. |
See ggamma
, the VGAM family function
for estimating the generalized gamma distribution
by maximum likelihood estimation,
for formulae and other details.
Apart from n
, all the above arguments may be vectors and
are recyled to the appropriate length if necessary.
dggamma
gives the density,
pggamma
gives the distribution function,
qggamma
gives the quantile function, and
rggamma
generates random deviates.
T. W. Yee
Stacy, E. W. and Mihram, G. A. (1965) Parameter estimation for a generalized gamma distribution. Technometrics, 7, 349–358.
## Not run: x=seq(0, 14, by=0.01); d=1.5; Scale=2; k=6 plot(x, dggamma(x, Scale, d, k), type="l", col="blue", ylim=c(0,1), main="Blue is density, red is cumulative distribution function", sub="Purple are 5,10,...,95 percentiles", las=1, ylab="") abline(h=0, col="blue", lty=2) lines(qggamma(seq(0.05,0.95,by=0.05), Scale, d, k), dggamma(qggamma(seq(0.05,0.95,by=0.05), Scale, d, k), Scale, d, k), col="purple", lty=3, type="h") lines(x, pggamma(x, Scale, d, k), type="l", col="red") abline(h=0, lty=2) ## End(Not run)