9.5 Rejection sampling

9.5.1 Description

An important method which does not make use of Markov chain methods but which helps to introduce the Metropolis–Hastings algorithm is rejection sampling or acceptance-rejection sampling. This is a method for use in connection with a density in the case where the normalizing constant K is quite possibly unknown, which, as remarked at the beginning of this chapter, is a typical situation occurring in connection with posterior distributions in Bayesian statistics. To use this method, we need to assume that there is a candidate density from which we can simulate samples and a constant c such that . Then, to obtain a random variable with density we proceed as follows:

1. Generate a variate Y from the density ;

2. Generate a value which is uniformly ...

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