| GammaDist {base} | R Documentation |
The Gamma Distribution
Usage
dgamma(x, shape, scale=1)
pgamma(q, shape, scale=1)
qgamma(p, shape, scale=1)
rgamma(n, shape, scale=1)
Arguments
x, q |
vector of quantiles. |
p |
vector of probabilites. |
n |
number of observations. |
shape, scale |
shape and scale parameters. |
Value
These functions provide information about the gamma
distribution with parameters shape and scale.
dgamma gives the density,
pgamma gives the distribution function
qgamma gives the quantile function
and
rgamma generates random deviates.
The gamma distribution with parameters shape = a and
scale = b has density
f(x) =
\frac{1}{{b}^{a} \Gamma (a)} {x}^{a-1} {e}^{-x/b}
for x > 0,
a > 0
and
b > 0.
See Also
gamma, dbeta.
Examples
-log(dgamma(1:4, shape=1))
p <- (1:9)/10
pgamma(qgamma(p,shape=2), shape=2)
1 - 1/exp(qgamma(p, shape=1))