Dirichlet_tpl.h

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namespace gum {

  // returns a sample from the Dirichlet distribution
  template < class URNG >
  INLINE Dirichlet::result_type Dirichlet::
                                operator()(URNG& generator, const Dirichlet::param_type& parm) {
    Size        size = Size(parm.size());
    result_type res(size);
    float       sum = 0.0f;
    while (sum == 0.0f) {
      for (Idx i = 0; i < size; ++i) {
        __gamma.param(std::gamma_distribution< float >::param_type(parm[i], 1));
        res[i] = __gamma(generator);
        sum += res[i];
      }
    }
    for (Idx i = 0; i < size; ++i) {
      res[i] /= sum;
    }
    return res;
  }

} /* namespace gum */