Function simulates trees based on given distributions and petterson
height function. Dbh can be simulated using normal ('norm'), weibull or
gamma distribution. Others might be added.
The par-list of each species needs the following named entries:
spp - species code, n - number of trees, ddist -
distribution of dbh, dpar - list of parameter of the distribution,
i.e. mu and sd for normal distribution and shape and
scale for weibull and gamma distribution. The latter both might use
lag to offset the estimated diameter by this amount.
See Also
petterson for the implemented height function and
dnorm, dweibull and dgamma for the
diameter distributions.