public function Collection::centroid in geoPHP 8

Same name and namespace in other branches

1. 7 geoPHP/lib/geometry/Collection.class.php \Collection::centroid()

Overrides Geometry::centroid

1 method overrides Collection::centroid()

Polygon::centroid in geoPHP/lib/geometry/Polygon.class.php

File

geoPHP/lib/geometry/Collection.class.php, line 43

Class

Collection

Collection: Abstract class for compound geometries

Code

public function centroid() {
  if ($this
    ->isEmpty()) {
    return NULL;
  }
  if ($this
    ->geos()) {
    $geos_centroid = $this
      ->geos()
      ->centroid();
    if ($geos_centroid
      ->typeName() == 'Point') {
      return geoPHP::geosToGeometry($this
        ->geos()
        ->centroid());
    }
  }

  // As a rough estimate, we say that the centroid of a colletion is the centroid of it's envelope
  // @@TODO: Make this the centroid of the convexHull
  // Note: Outside of polygons, geometryCollections and the trivial case of points, there is no standard on what a "centroid" is
  $centroid = $this
    ->envelope()
    ->centroid();
  return $centroid;
}