dshster/application.js

## application.js
const margin = 200;
const theta = 0.2;

function getRandomCoords({ width, height }) {
  return {
    top: Math.random() * (width - margin) + margin / 2,
    left: Math.random() * (height - margin) + margin / 2,
  };
}

function getRandomShape() {
  const width = map.clientWidth;
  const height = map.clientHeight;

  const center = getRandomCoords({ width, height });
  const corners = [...new Array(10).keys()];

  return corners
    .map(point => Math.random() * 360 * Math.PI / 180)
    .sort((a, b) => a - b)
    .reduce((list, point) => {
      const prev = list.length && list[list.length - 1];

      if (point - prev > theta) {
        list.push(point);
      }

      return list;
    }, [])
    .map(point => {
      const diameter = Math.random() * 50 + 25;

      const x = diameter * Math.cos(point);
      const y = diameter * Math.sin(point);

      return { top: center.top + y, left: center.left + x };
    });
}

ymaps.ready(() => {
  const map = document.getElementById('map');
  const seed = document.getElementById('seed');
  const list = document.getElementById('list');

  const yMap = new ymaps.Map('map', {
    center: [55.751574, 37.573856],
    zoom: 9
  }, {
    searchControlProvider: 'yandex#search'
  });

  const projection = yMap.options.get('projection');

  seed.addEventListener('click', () => {
    const coords = getRandomShape();
    const shape = coords.map(point => projection.fromGlobalPixels(
      yMap.converter.pageToGlobal([point.left, point.top]), yMap.getZoom()
    ));

    const myPolygon = new ymaps.Polygon([
      shape
    ], {
      hintContent: "Многоугольник"
    }, {
      fillColor: '#00FF0088',
      strokeWidth: 5
    });

    yMap.geoObjects.add(myPolygon);
  });

  list.addEventListener('click', () => {
    const list = [];

    yMap.geoObjects.each(geo => {
      list.push(geo.geometry.getCoordinates()[0])
    });

    console.log(list);
  });
});

## index.html
<!DOCTYPE html>
<html>
<head>
  <title>Примеры. Метка</title>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
  <script src="http://api-maps.yandex.ru/2.1/?lang=ru_RU" type="text/javascript"></script>
  <script src="application.js" type="text/javascript"></script>
  <style>
    #map {
      width: 800px;
      height: 600px;
      padding: 0;
      margin: 0;
      border: 1px solid #faf;
      position: relative;
    }
    .point {
      position: absolute;
      width: 10px;
      height: 10px;
      margin-top: -5px;
      margin-left: -5px;
    }
  </style>
</head>
<body>
<div id="map"></div>
<button id="seed">seed</button>
<button id="list">list</button>
</body>
</html>
	const margin = 200;
	const theta = 0.2;

	function getRandomCoords({ width, height }) {
	return {
	top: Math.random() * (width - margin) + margin / 2,
	left: Math.random() * (height - margin) + margin / 2,
	};
	}

	function getRandomShape() {
	const width = map.clientWidth;
	const height = map.clientHeight;

	const center = getRandomCoords({ width, height });
	const corners = [...new Array(10).keys()];

	return corners
	.map(point => Math.random() * 360 * Math.PI / 180)
	.sort((a, b) => a - b)
	.reduce((list, point) => {
	const prev = list.length && list[list.length - 1];

	if (point - prev > theta) {
	list.push(point);
	}

	return list;
	}, [])
	.map(point => {
	const diameter = Math.random() * 50 + 25;

	const x = diameter * Math.cos(point);
	const y = diameter * Math.sin(point);

	return { top: center.top + y, left: center.left + x };
	});
	}

	ymaps.ready(() => {
	const map = document.getElementById('map');
	const seed = document.getElementById('seed');
	const list = document.getElementById('list');

	const yMap = new ymaps.Map('map', {
	center: [55.751574, 37.573856],
	zoom: 9
	}, {
	searchControlProvider: 'yandex#search'
	});

	const projection = yMap.options.get('projection');

	seed.addEventListener('click', () => {
	const coords = getRandomShape();
	const shape = coords.map(point => projection.fromGlobalPixels(
	yMap.converter.pageToGlobal([point.left, point.top]), yMap.getZoom()
	));

	const myPolygon = new ymaps.Polygon([
	shape
	], {
	hintContent: "Многоугольник"
	}, {
	fillColor: '#00FF0088',
	strokeWidth: 5
	});

	yMap.geoObjects.add(myPolygon);
	});

	list.addEventListener('click', () => {
	const list = [];

	yMap.geoObjects.each(geo => {
	list.push(geo.geometry.getCoordinates()[0])
	});

	console.log(list);
	});
	});
	<!DOCTYPE html>
	<html>
	<head>
	<title>Примеры. Метка</title>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
	<script src="http://api-maps.yandex.ru/2.1/?lang=ru_RU" type="text/javascript"></script>
	<script src="application.js" type="text/javascript"></script>
	<style>
	#map {
	width: 800px;
	height: 600px;
	padding: 0;
	margin: 0;
	border: 1px solid #faf;
	position: relative;
	}
	.point {
	position: absolute;
	width: 10px;
	height: 10px;
	margin-top: -5px;
	margin-left: -5px;
	}
	</style>
	</head>
	<body>
	<div id="map"></div>
	<button id="seed">seed</button>
	<button id="list">list</button>
	</body>
	</html>