PostGIS  2.5.0beta2dev-r@@SVN_REVISION@@

◆ geography_centroid_from_wpoints()

LWPOINT * geography_centroid_from_wpoints ( const uint32_t  srid,
const POINT3DM points,
const uint32_t  size 
)

Convert lat-lon-points to x-y-z-coordinates, calculate a weighted average point and return lat-lon-coordinated.

Definition at line 180 of file geography_centroid.c.

References cart_to_lwpoint(), lonlat_to_cart(), lwfree(), POINT3DM::m, pixval::x, POINT3D::x, pixval::y, POINT3D::y, and POINT3D::z.

Referenced by geography_centroid(), geography_centroid_from_mline(), and geography_centroid_from_mpoly().

181 {
182  double_t x_sum = 0;
183  double_t y_sum = 0;
184  double_t z_sum = 0;
185  double_t weight_sum = 0;
186 
187  double_t weight = 1;
188  POINT3D* point;
189 
190  uint32_t i;
191  for (i = 0; i < size; i++ )
192  {
193  point = lonlat_to_cart(points[i].x, points[i].y);
194  weight = points[i].m;
195 
196  x_sum += point->x * weight;
197  y_sum += point->y * weight;
198  z_sum += point->z * weight;
199 
200  weight_sum += weight;
201 
202  lwfree(point);
203  }
204 
205  return cart_to_lwpoint(x_sum, y_sum, z_sum, weight_sum, srid);
206 }
LWPOINT * cart_to_lwpoint(const double_t x_sum, const double_t y_sum, const double_t z_sum, const double_t weight_sum, const uint32_t srid)
void lwfree(void *mem)
Definition: lwutil.c:244
double y
Definition: liblwgeom.h:342
POINT3D * lonlat_to_cart(const double_t raw_lon, const double_t raw_lat)
double x
Definition: liblwgeom.h:342
double z
Definition: liblwgeom.h:342
unsigned int uint32_t
Definition: uthash.h:78
double m
Definition: liblwgeom.h:348
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