std::cauchy_distribution

#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <map>
#include <random>
#include <vector>
 
template<int Height = 5, int BarWidth = 1, int Padding = 1, int Offset = 0, class Seq>
void draw_vbars(Seq&& s, const bool DrawMinMax = true)
{
 static_assert(0 < Height and 0 < BarWidth and 0 <= Padding and 0 <= Offset);
 
 auto cout_n = [](auto&& v, int n = 1)
 {
 while (n-- > 0)
 std::cout << v;
 };
 
 const auto [min, max] = std::minmax_element (std::cbegin (s), std::cend (s));
 
 std::vector <std::div_t > qr;
 for (typedef decltype(*std::cbegin (s)) V; V e : s)
 qr.push_back(std::div (std::lerp (V(0), 8 * Height,
 (e - *min) / (*max - *min)), 8));
 
 for (auto h{Height}; h-- > 0; cout_n('\n'))
 {
 cout_n(' ', Offset);
 
 for (auto dv : qr)
 {
 const auto q{dv.quot}, r{dv.rem};
 unsigned char d[]{0xe2, 0x96, 0x88, 0}; // Full Block: '█'
 q < h ? d[0] = ' ', d[1] = 0 : q == h ? d[2] -= (7 - r) : 0;
 cout_n(d, BarWidth), cout_n(' ', Padding);
 }
 
 if (DrawMinMax && Height > 1)
 Height - 1 == h ? std::cout << "┬ " << *max:
 h ? std::cout << "│ "
 : std::cout << "┴ " << *min;
 }
}
 
int main()
{
 std::random_device rd{};
 std::mt19937 gen{rd()};
 
 auto cauchy = [&gen](const float x0, const float γ)
 {
 std::cauchy_distribution<float> d{x0 /* a */, γ /* b */};
 
 const int norm = 1'00'00;
 const float cutoff = 0.005f;
 
 std::map <int, int> hist{};
 for (int n = 0; n != norm; ++n)
 ++hist[std::round (d(gen))];
 
 std::vector <float> bars;
 std::vector <int> indices;
 for (auto const& [n, p] : hist)
 if (float x = p * (1.0 / norm); cutoff < x)
 {
 bars.push_back(x);
 indices.push_back(n);
 }
 
 std::cout << "x0 = " << x0 << ", γ = " << γ << ":\n";
 draw_vbars<4,3>(bars);
 for (int n : indices)
 std::cout << std::setw (2) << n << " ";
 std::cout << "\n\n";
 };
 
 cauchy(/* x0 = */ -2.0f, /* γ = */ 0.50f);
 cauchy(/* x0 = */ +0.0f, /* γ = */ 1.25f);
}

x0 = -2, γ = 0.5:
 ███ ┬ 0.5006
 ███ │
 ▂▂▂ ███ ▁▁▁ │
▁▁▁ ▁▁▁ ▁▁▁ ▃▃▃ ███ ███ ███ ▂▂▂ ▁▁▁ ▁▁▁ ▁▁▁ ┴ 0.0076
-7 -6 -5 -4 -3 -2 -1 0 1 2 3
 
x0 = 0, γ = 1.25:
 ███ ┬ 0.2539
 ▅▅▅ ███ ▃▃▃ │
 ▁▁▁ ███ ███ ███ ▁▁▁ │
▁▁▁ ▁▁▁ ▁▁▁ ▁▁▁ ▃▃▃ ▅▅▅ ███ ███ ███ ███ ███ ▅▅▅ ▃▃▃ ▂▂▂ ▁▁▁ ▁▁▁ ▁▁▁ ┴ 0.0058
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 9