# simplexUC: Simplex Distribution In VGAM: Vector Generalized Linear and Additive Models

## Description

Density function, and random generation for the simplex distribution.

## Usage

 ```1 2``` ```dsimplex(x, mu = 0.5, dispersion = 1, log = FALSE) rsimplex(n, mu = 0.5, dispersion = 1) ```

## Arguments

 `x` Vector of quantiles. The support of the distribution is the interval (0,1). `mu, dispersion` Mean and dispersion parameters. The former lies in the interval (0,1) and the latter is positive. `n, log` Same usage as `runif`.

## Details

The VGAM family function `simplex` fits this model; see that online help for more information. For `rsimplex()` the rejection method is used; it may be very slow if the density is highly peaked, and will fail if the density asymptotes at the boundary.

## Value

`dsimplex(x)` gives the density function, `rsimplex(n)` gives n random variates.

## Author(s)

T. W. Yee

`simplex`.
 ```1 2 3 4 5 6 7 8 9``` ```sigma <- c(4, 2, 1) # Dispersion parameter mymu <- c(0.1, 0.5, 0.7); xxx <- seq(0, 1, len = 501) ## Not run: par(mfrow = c(3, 3)) # Figure 2.1 of Song (2007) for (iii in 1:3) for (jjj in 1:3) { plot(xxx, dsimplex(xxx, mymu[jjj], sigma[iii]), type = "l", col = "blue", xlab = "", ylab = "", main = paste("mu = ", mymu[jjj], ", sigma = ", sigma[iii], sep = "")) } ## End(Not run) ```