single artificial neuron with eigen

simple_neuron.cpp

#include <iostream>
#include <random>
#include <cmath>
#include <Eigen/Core>
#include "pcg_random.hpp"

using namespace Eigen;

template<unsigned int Size>
struct neuron {
  VectorXd weights;
  double bias;

  neuron() {
    pcg_extras::seed_seq_from<std::random_device> seed_source;

    pcg32 rng(seed_source);

    std::uniform_real_distribution<> real_dist(-0.5, 0.5);
    
    weights = VectorXd(Size);
    for (int i = 0; i < Size; i++) {
      weights[i] = real_dist(rng);
    }

    bias = real_dist(rng);
    std::cout << "weights = " << weights << std::endl;
    std::cout << "bias = " << bias << std::endl;
  }

  double sense(VectorXd input) {    
    return tanh(weights.dot(input) + bias);
  }
};

int main()
{
  neuron<2> n;

  VectorXd input(2);
  input << 1.0, 2.0;
  std::cout << n.sense(input) << '\n';
  std::cin.get();
}