/**
* Takes a set of features, calculates the bbox of all input features, and returns a bounding box.
*
* @name bbox
* @param {(Feature|FeatureCollection)} geojson input features
* @return {Array<number>} bbox extent in [minX, minY, maxX, maxY] order
* @example
* var pt1 = point([114.175329, 22.2524])
* var pt2 = point([114.170007, 22.267969])
* var pt3 = point([114.200649, 22.274641])
* var pt4 = point([114.200649, 22.274641])
* var pt5 = point([114.186744, 22.265745])
* var features = featureCollection([pt1, pt2, pt3, pt4, pt5])
*
* var bbox = turf.bbox(features);
*
* var bboxPolygon = turf.bboxPolygon(bbox);
*
* //=bbox
*
* //=bboxPolygon
*/
public static List <double> Bbox(IGeoJSONObject geojson)
{
var bbox = new List <double>()
{
double.PositiveInfinity, double.PositiveInfinity, double.NegativeInfinity, double.NegativeInfinity
};
Turf.CoordEach(geojson, (List <double> coord) => {
if (bbox[0] > coord[0])
{
bbox[0] = coord[0];
}
if (bbox[1] > coord[1])
{
bbox[1] = coord[1];
}
if (bbox[2] < coord[0])
{
bbox[2] = coord[0];
}
if (bbox[3] < coord[1])
{
bbox[3] = coord[1];
}
});
return(bbox);
}
/**
* Takes one or more features and calculates the centroid using
* the mean of all vertices.
* This lessens the effect of small islands and artifacts when calculating
* the centroid of a set of polygons.
*
* @name centroid
* @param {(Feature|FeatureCollection)} features input features
* @return {Feature<Point>} the centroid of the input features
* @example
* var poly = {
* "type": "Feature",
* "properties": {},
* "geometry": {
* "type": "Polygon",
* "coordinates": [[
* [105.818939,21.004714],
* [105.818939,21.061754],
* [105.890007,21.061754],
* [105.890007,21.004714],
* [105.818939,21.004714]
* ]]
* }
* };
*
* var centroidPt = turf.centroid(poly);
*
* var result = {
* "type": "FeatureCollection",
* "features": [poly, centroidPt]
* };
*
* //=result
*/
public static Feature Centroid(IGeoJSONObject features)
{
double xSum = 0;
double ySum = 0;
int len = 0;
Turf.CoordEach(features, (List <double> coord) => {
xSum += coord[0];
ySum += coord[1];
len++;
}, true);
return(Turf.Point(new double[] { xSum / (double)len, ySum / (double)len }));
}