custom split

/////////////////////////////////////////////////////////////////////////////////////////////
//setting up the map http://jsfiddle.net/fq7vu2rn/3///
/////////////////////////////////////////////////////////////////////////////////////////////

// set center coordinates
var centerlat = 41.81173; 
var centerlon = -87.666227;

// set default zoom level
var zoomLevel = 10; 

// initialize map
var map = L.map('map').setView([centerlat,centerlon], zoomLevel);
 
// set source for map tiles
ATTR = '&copy; <a href="http://openstreetmap.org">OpenStreetMap</a> contributors, ' +
'<a href="http://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a> | ' +
'&copy; <a href="http://cartodb.com/attributions">CartoDB</a>';

CDB_URL = 'http://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png';

// add tiles to map
L.tileLayer(CDB_URL, {attribution: ATTR}).addTo(map);

var bbox =[-87.75613096987291,41.7218260301271,-87.5763230301271,41.9016339698729];

var bb = {xmin: -87.75613096987291, ymin: 41.7218260301271,xmax:-87.5763230301271,ymax: 41.9016339698729};

var xmin = -87.75613096987291;
var ymin = 41.7218260301271;
var xmax = -87.5763230301271;
var ymax = 41.9016339698729;
var bboxPoly = L.geoJson(turf.bboxPolygon(bbox));
//L.geoJson(turf.bboxPolygon(bbox)).addTo(map);
var area = turf.area(turf.bboxPolygon(bbox));
console.log(Math.sqrt(area)/1000);
//L.geoJson(area).addTo(map);
//var points = turf.explode(turf.bboxPolygon(bbox));

var units = 'kilometers';
//var distance = turf.distance(from, to, units);
var points = turf.multiPoint([[xmin,ymin], [xmax,ymax]]);
//L.geoJson(points).addTo(map);
var distance = turf.distance([xmin,ymax], [xmin,ymin], 'kilometers');
console.log(distance);
var cellWidth = distance/2;

//create hex grid and count points within each cell
var squaregrid = turf.squareGrid(bbox, cellWidth, units);
//collect points into array
/*
features = [];
var midpointed1 = turf.midpoint([xmin,ymin], [xmin,ymax]);


L.geoJson(midpointed1).addTo(map);
features.push(midpointed1);

var midpointed2 = turf.midpoint([xmax,ymin], [xmax,ymax]);


L.geoJson(midpointed2).addTo(map);
features.push(midpointed2);
var midpointed3 = turf.midpoint([xmax,ymin], [xmin,ymin]);

L.geoJson(midpointed3).addTo(map);
features.push(midpointed3);

var midpointed4 = turf.midpoint([xmin,ymax], [xmax,ymax]);
features.push(midpointed4);

L.geoJson(midpointed4).addTo(map);

var centroid = turf.centroid(turf.bboxPolygon(bbox));
//L.geoJson(centroid).addTo(map);
features.push(centroid);

L.geoJson(turf.lineString([midpointed3['geometry']['coordinates'], centroid['geometry']['coordinates']])).addTo(map);

var fc = turf.featureCollection(features);*/

function splitBbox(bbox) {
    var halfWidth = (bbox.xmax - bbox.xmin) / 2.0,
        halfHeight = (bbox.ymax - bbox.ymin) / 2.0;
    return [
        {xmin: bbox.xmin, ymin: bbox.ymin, ymax: bbox.ymin + halfHeight, xmax: bbox.xmin + halfWidth},
        {xmin: bbox.xmin + halfWidth, ymin: bbox.ymin, ymax: bbox.ymin + halfHeight, xmax: bbox.xmax},
        {xmin: bbox.xmin, ymin: bbox.ymin + halfHeight, xmax: bbox.xmin + halfWidth, ymax: bbox.ymax},
        {xmin: bbox.xmin + halfWidth, ymin: bbox.ymin + halfHeight, xmax: bbox.xmax, ymax: bbox.ymax}
    ];
}
function getQuads (bb) {
var split = splitBbox(bb);
var quads = [];
for (var i = 0; i < split.length; i++) {
var test = quads.push(turf.bboxPolygon([split[i]['xmin'],split[i]['ymin'], split[i]['xmax'],split[i]['ymax']] ));
console.log(quads);
}
var fc = turf.featureCollection(quads);
L.geoJson(fc).addTo(map);
console.log(fc);
return quads;

}

var split1 = getQuads(bb);
var split2 = getQuads(split1[0]);
console.log(getQuads);