GeoJSON

geoSON

geoJSONは、位置データと属性データを格納するフォーマットです.
(経度、緯度)順に格納します.
データ容量は他のフォーマットよりも小さく、XMLよりも使いやすい.
簡単に客体化できます.

geoJSON形式

{
	"type" : "FeatureCollection",
	"features" : [
		/* features 안에 실제 데이터가 담김 */
		"type" : "Feature",
		"geometry" : {
			/* geometry 안에 종류(type)와 좌표(coordinates)가 저장됨 */
			"type" : "Point",
			"coordinates" : [102.0, 0.5]
		}
		"properties" : {
			/* properties 안에 속성 정보가 key-values로 저장됨 */
			"prop0" : "value0",
			"prop1" : {"this" : "that"}
		}
	]
}

プライマリジオメトリ

1.Point：ポイント

```json
/* Point */
{
	"type" : "Point",
	"coordinates" : [30, 10]
}

/* MultiPoint */
{
	"type": "MultiPoint",
	"coordinates": [
		[10, 40], [40, 30], [20, 20], [30, 10]
	]
}
```

2.LineString（ポリライン）：線分

```json
/* LineString */
{
	"type" : "LineString",
	"coordinates" : [
		[30, 10], [10, 30], [40, 40]
	]
}

/* MultiLineString */
{
	"type": "MultiLineString",
	"coordinates": [
		[[10, 10], [20, 20], [10, 40]],
		[[40, 40], [30, 30], [40, 20], [30, 10]]
	]
}
```

3.Polygon:多角形(穴なし)

```json
/* Polygon */
{
	"type" : "Polygon",
	"coordinates" : [
		[[30, 10], [40, 40], [20, 40], [10, 20], [30, 10]]
	]
}

/* MultiPolygon */
{
	"type": "MultiPolygon",
	"coordinates": [
		[
			[[30, 20], [45, 40], [10, 40], [30, 20]]
		],
		[
			[[15, 5], [40, 10], [10, 20], [5, 10], [15, 5]]
		]
	]
}
```

4.Polygon:多角形(穴付き)

```
/* Polygon */
{
	"type" : "Polygon",
	"coordinates" : [
		[[35, 10], [45, 45], [15, 40], [10, 20], [35, 10]],
		[[20, 30], [35, 35], [30, 20], [20, 30]]
	]
}

/* MultiPolygon */
{
	"type": "MultiPolygon",
	"coordinates": [
		[
			[[40, 40], [20, 45], [45, 30], [40, 40]]
		],
		[
			[[20, 35], [10, 30], [10, 10], [30, 5], [45, 20], [20, 35]],
			[[30, 20], [20, 15], [20, 25], [30, 20]]
		]
	]
}
```