dgamma(x, shape, scale=1) pgamma(q, shape, scale=1) qgamma(p, shape, scale=1) rgamma(n, shape, scale=1)
x,q
| vector of quantiles. |
p
| vector of probabilites. |
n
| number of observations. |
shape, scale
| shape and scale parameters. |
shape and scale.
dgamma gives the density,
pgamma gives the distribution function
qgamma gives the quantile function
and
rgamma generates random deviates.
If scale is omitted, it assumes the default value of 1.
The gamma distribution with parameters shape = a and
scale = b has density
f(x) = 1/(b^a Gamma(a)) x^(a-1) e^-(x/b)
for x > 0, a > 0 and b > 0.gamma for the gamma function, dbeta for
the beta distribution and dchisq for the chi-square
distribution which is a special case of the gamma distribution.-log(dgamma(1:4, shape=1)) p <- (1:9)/10 pgamma(qgamma(p,shape=2), shape=2) 1 - 1/exp(qgamma(p, shape=1))