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oneapi::mkl::rng::gaussian_mv
Generates random numbers from multivariate normal distribution.
Description
The class object is used in the oneapi::mkl::rng::generate function to provide random numbers with d-variate normal (Gaussian) distribution with mean (a) and variance-covariance matrix C, where a ∈ Rd ; C is d x d symmetric positive-definite matrix.
The probability density function is given by:
 
   where x``∈ ``Rd .
Matrix C can be represented as C = TTT, where T is a lower triangular matrix - Cholesky factor of C.
API
Syntax
template<typename RealType = float, layout Layout = layout::packed,
         typename Method = gaussian_mv_method::by_default>
class gaussian_mv {
public:
  using method_type = Method;
  using result_type = RealType;
  static constexpr layout layout_type = Layout;
  explicit gaussian_mv(std::uint32_t dimen, std::vector<RealType> mean,
                       std::vector<RealType> matrix); // deprecated since oneMKL 2023.0
  explicit gaussian_mv(std::uint32_t dimen, sycl::span<RealType> mean,
                       sycl::span<RealType> matrix);
  explicit gaussian_mv(const param_type& pt);
  std::uint32_t dimen() const;
  std::vector<RealType> mean() const;
  std::vector<RealType> matrix() const;
  param_type param() const;
  void param(const param_type& pt);
}; 
   Devices supported: CPU and GPU.
Include Files
oneapi/mkl/rng.hpp
Template Parameters
Name  |  
        Description  |  
       
|---|---|
typename RealType = float  |  
        Type of the produced values. The specific values are as follows: float double  |  
       
layout Layout = layout::packed  |  
        Type of the matrix storage. The specific values are as follows: layout::packed layout::full layout::diagonal See brief descriptions of the methods in Distributions Template Parameter Method.  |  
       
typename Method = oneapi::mkl::rng::gaussian_mv_method::by_default  |  
        Generation method. The specific values are as follows: oneapi::mkl::rng::gaussian_mv_method::box_muller oneapi::mkl::rng::gaussian_mv_method::box_muller2 oneapi::mkl::rng::gaussian_mv_method::icdf See brief descriptions of the methods in Distributions Template Parameter Method.  |  
       
Input Parameters
Name  |  
        Type  |  
        Description  |  
       
|---|---|---|
dimen  |  
        std::uint32_t  |  
        Dimension of output random vectors  |  
       
mean  |  
        sycl::span< RealType> (float, double  |  
        Mean span a of dimension d.  |  
       
matrix  |  
        sycl::span< RealType> (float, double  |  
        Variance-covariance matrix C.  |  
       
- explicit gaussian_mv(std::uint32_t dimen, std::vector<RealType> mean, std::vector<RealType> matrix); is deprecated and will be removed in one of the next releases. Use explicit gaussian_mv(std::uint32_t dimen, sycl::span<RealType> mean, sycl::span<RealType> matrix); instead.
 When passing a sycl::span that is constructed over a user’s memory to the constructor, users must manage the memory under sycl::span by themselves. They must not destroy the memory while data are processed.