AM_find_gamma_Pois {AntMAN} | R Documentation |
Once the prior on the number of mixture components M is assumed to be a Shifted Poisson of parameter Lambda
,
this function adopts a bisection method to find the value of γ such that the induced distribution
on the number of clusters is centered around a user specifed value K^{*}, i.e. the function uses a bisection
method to solve for γ (Argiento and Iorio 2019). The user can provide a lower γ_{l}
and an upper γ_{u} bound for the possible values of γ. The default values are γ_l= 10^{-3} and γ_{u}=10.
A defaault value for the tolerance is ε=0.1. Moreover, after a maximum number of iteration (default is 31),
the function stops warning that convergence has not bee reached.
AM_find_gamma_Pois( n, Lambda, Kstar = 6, gam_min = 1e-04, gam_max = 10, tolerance = 0.1 )
n |
The sample size. |
Lambda |
The parameter of the Shifted Poisson for the number of components of the mixture. |
Kstar |
The mean number of clusters the user wants to specify. |
gam_min |
The lower bound of the interval in which |
gam_max |
The upper bound of the interval in which |
tolerance |
Level of tolerance of the method. |
A value of gamma
such that E(K)=K^{*}
n <- 82 Lam <- 11 gam_po <- AM_find_gamma_Pois(n,Lam,Kstar=6, gam_min=0.0001,gam_max=10, tolerance=0.1) prior_K_po <- AM_prior_K_Pois(n,gam_po,Lam) prior_K_po%*%1:n