I am interested in generating numbers from a truncated Dirichlet distribution, upperly bounded by a certain value. As a simple example:

```
library(DirichletReg)
ub=0.2
DirichletReg::rdirichlet(1,alpha=rep(1,times=10))
```

This code generates 10 random numbers from the Dirichlet distribution with all concentration parameters set to 1.

Does anyone know how could I do the same, truncating the distribution by an upper bound `ub`

?

Thanks in advance for any help!