aGrUM  0.13.2
Dirichlet_tpl.h
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27 namespace gum {
28 
29  // returns a sample from the Dirichlet distribution
30  template < class URNG >
32  operator()(URNG& generator, const Dirichlet::param_type& parm) {
33  Size size = Size(parm.size());
34  result_type res(size);
35  float sum = 0.0f;
36  while (sum == 0.0f) {
37  for (Idx i = 0; i < size; ++i) {
38  __gamma.param(std::gamma_distribution< float >::param_type(parm[i], 1));
39  res[i] = __gamma(generator);
40  sum += res[i];
41  }
42  }
43  for (Idx i = 0; i < size; ++i) {
44  res[i] /= sum;
45  }
46  return res;
47  }
48 
49 } /* namespace gum */
unsigned long Size
In aGrUM, hashed values are unsigned long int.
Definition: types.h:50
gum is the global namespace for all aGrUM entities
Definition: agrum.h:25
std::gamma_distribution< float > __gamma
The gamma distribution used to compute the Dirichlet unnormalized samples.
Definition: Dirichlet.h:172
std::vector< float > param_type
The parameter type.
Definition: Dirichlet.h:50
std::vector< float > result_type
The type for the samples generated.
Definition: Dirichlet.h:53
result_type operator()()
Returns a sample from the Dirichlet distribution.
Definition: Dirichlet_inl.h:72
unsigned long Idx
Type for indexes.
Definition: types.h:43