fast clasterization by k-mean+grid on javascript

grid.clasterization.js

const grid_clasterization = (points, quadrant_size, grid_size, x_max, y_max) => {
  const quadrants = Array.apply(null, {length: Math.ceil(grid_size/quadrant_size)}).map(e => 0);
  const grid_width = Math.sqrt(grid_size);
  const quadrant_width = Math.sqrt(quadrant_size);
 
  const grid_quadro_x_size = (x_max / grid_width)*quadrant_width;
  const grid_quadro_y_size = (y_max / grid_width)*quadrant_width;
 
  for(const point of points) {
    const x_index = (Math.ceil(point.x/grid_quadro_x_size) - 1);
    const y_index = (Math.ceil(point.y/grid_quadro_y_size) - 1);
 
    const index = x_index + (quadrant_width*y_index);
    quadrants[index]++;
  }
  
  return quadrants;
};

// ========== test grid_clasterization

const print_quadro_array = array => {
  const size = Math.sqrt(array.length);
  let result = '';
  for(let i = 0; i < size; ++i) {
    result = `${result}\n`;
    for(let j = 0; j < size; ++j) {
      result = `${result} ${array[i + size*j]}`;
    }
  }
  return result;
};

const points = [
  {x:0.9, y:0.9},
  {x:0.91, y:0.92},
  {x:0.3, y:0.3},
  {x:0.35, y:0.35},
];

const quadrant_size = 9; 
const grid_size = 81;
const x_max = 1;
const y_max = 1;

const quadrants = grid_clasterization(points, quadrant_size, grid_size, x_max, y_max);

print_quadro_array(quadrants);