rdiric {VGAM} | R Documentation |
Generates Dirichlet random variates.
rdiric(n, shape, dimension = NULL)
n |
number of observations. |
shape |
the shape parameters. These must be positive.
If dimension is specifed, values
are recycled if necessary to length dimension .
|
dimension |
the dimension of the distribution.
If dimension is not numeric then it is taken to be
length(shape) .
|
This function is based on a relationship between the gamma and Dirichlet distribution. Random gamma variates are generated, and then Dirichlet random variates are formed from these.
A n
by dimension
matrix of Dirichlet random variates.
Each element is positive, and each row will sum to unity.
Thomas W. Yee
Lange, K. (2002) Mathematical and Statistical Methods for Genetic Analysis, 2nd ed. New York: Springer-Verlag.
dirichlet
is a VGAM family function for
fitting a Dirichlet distribution to data.
y = rdiric(n=1000, shape=c(3, 1, 4)) fit = vglm(y ~ 1, dirichlet, trace = TRUE, crit="c") Coef(fit) coef(fit, matrix=TRUE)