Изменение масштаба Яндекс.Карты

HTML

<script src="//api-maps.yandex.ru/2.1/?lang=ru_RU"></script>
<form class="contacts__map-toggle radio-btn">

  <label>

    <input class="radio-btn__input hidden-visible" type="radio" name="map" value="master" checked="checked">
    <span class="radio-btn__label">Несколько меток</span>

  </label>

  <label>

    <input class="radio-btn__input hidden-visible" type="radio" name="map" value="service">
    <span class="radio-btn__label">Одна метка</span>

  </label>

</form>
<div id="map"></div>

CSS

html, body, #map {
            width: 100%; height: 100%; padding: 0; margin: 0;
        }

JavaScript

var boxMap = document.querySelector('.contacts__map');
var yaMap = window.yaMap || {};

yaMap.onepoint = [
		{
	"id"    : "6224",
	"coord" : [55.76793956897819,37.60222899999999],

}			];

yaMap.manypoints = [
		{
	"id"    : "6234",
	"coord" : [55.692222,37.532778]

},
					{
	"id"    : "6233",
	"coord" : [55.743889,37.4975]

},
					{
	"id"    : "6232",
	"coord" : [55.793611,37.5875]

}			];

function initMap() {

	var myMap = new ymaps.Map('map', {
		center: [55.74, 37.58],
		zoom: 11,
		controls: []
	});

	var zoomControl = new ymaps.control.ZoomControl({
		options: {
			visible: true
		}
	});

	myMap.controls.add(zoomControl);

	var PlacemarkCollectionManyitem = new ymaps.GeoObjectCollection(null, {
  balloonContent: 'Текст при клике',
	hintContent: 'Текст при наведении'
});

	var PlacemarkCollectionOnepoint = new ymaps.GeoObjectCollection(null, {
		balloonContent: 'Текст при клике',
		hintContent: 'Текст при наведении'
});

	myMap.behaviors.disable('scrollZoom');

	ymaps.ready(function () {

		function setPoint(obj,collection){

			var myPlacemark = new ymaps.Placemark(obj.coord);

			collection.add(myPlacemark);

		}

		for (var i in yaMap.onepoint) {

//								setPoint(yaMap.onepoint[i],PlacemarkCollectionOnepoint);

			var myPlacemark = new ymaps.Placemark(yaMap.onepoint[i].coord);
			PlacemarkCollectionOnepoint.add(myPlacemark);

		}

		for (var i in yaMap.manypoints) {

			setPoint(yaMap.manypoints[i],PlacemarkCollectionManyitem);

		}

		PlacemarkCollectionOnepoint.options.set('visible', false);

		myMap.geoObjects.add(PlacemarkCollectionManyitem);
		myMap.geoObjects.add(PlacemarkCollectionOnepoint);

		Array.prototype.forEach.call(document.querySelectorAll('.contacts__map-toggle [name="map"]'), function(input){

			input.addEventListener('change',function(){

				if(this.value == "master"){

					PlacemarkCollectionManyitem.options.set('visible', true);
					PlacemarkCollectionOnepoint.options.set('visible', false);

				}

				if(this.value ==...