index.js

var point = require('turf-point');
var featurecollection = require('turf-featurecollection');
var distance = require('turf-distance');
/**
 * Takes a bounding box and a cell depth and returns a set of {@link Point|points} in a grid.
 *
 * @module turf/point-grid
 * @category interpolation
 * @param {Array<number>} extent extent in [minX, minY, maxX, maxY] order
 * @param {Number} cellWidth the distance across each cell
 * @param {String} units used in calculating cellWidth ('miles' or 'kilometers')
 * @return {FeatureCollection<Point>} grid of points
 * @example
 * var extent = [-70.823364, -33.553984, -70.473175, -33.302986];
 * var cellWidth = 3;
 * var units = 'miles';
 *
 * var grid = turf.pointGrid(extent, cellWidth, units);
 *
 * //=grid
 */
module.exports = function (bbox, cell, units) {
  var fc = featurecollection([]);
  var xFraction = cell / (distance(point([bbox[0], bbox[1]]), point([bbox[2], bbox[1]]), units));
  var cellWidth = xFraction * (bbox[2] - bbox[0]);
  var yFraction = cell / (distance(point([bbox[0], bbox[1]]), point([bbox[0], bbox[3]]), units));
  var cellHeight = yFraction * (bbox[3] - bbox[1]);

  var currentX = bbox[0];
  while (currentX <= bbox[2]) {
    var currentY = bbox[1];
    while (currentY <= bbox[3]) {
      fc.features.push(point([currentX, currentY]));

      currentY += cellHeight;
    }
    currentX += cellWidth;
  }

  return fc;
};