PostGIS  2.5.0beta1dev-r@@SVN_REVISION@@

◆ nd_box_overlap()

static int nd_box_overlap ( const ND_STATS nd_stats,
const ND_BOX nd_box,
ND_IBOX nd_ibox 
)
inlinestatic

What stats cells overlap with this ND_BOX? Put the lowest cell addresses in ND_IBOX->min and the highest in ND_IBOX->max.

Definition at line 666 of file gserialized_estimate.c.

References ND_STATS_T::extent, ND_BOX_T::max, ND_IBOX_T::max, ND_BOX_T::min, ND_IBOX_T::min, nd_box_to_json(), ND_STATS_T::ndims, and ND_STATS_T::size.

Referenced by compute_gserialized_stats_mode(), estimate_join_selectivity(), and estimate_selectivity().

667 {
668  int d;
669 
670  POSTGIS_DEBUGF(4, " nd_box: %s", nd_box_to_json(nd_box, nd_stats->ndims));
671 
672  /* Initialize ibox */
673  memset(nd_ibox, 0, sizeof(ND_IBOX));
674 
675  /* In each dimension... */
676  for ( d = 0; d < nd_stats->ndims; d++ )
677  {
678  double smin = nd_stats->extent.min[d];
679  double smax = nd_stats->extent.max[d];
680  double width = smax - smin;
681  int size = roundf(nd_stats->size[d]);
682 
683  /* ... find cells the box overlaps with in this dimension */
684  nd_ibox->min[d] = floor(size * (nd_box->min[d] - smin) / width);
685  nd_ibox->max[d] = floor(size * (nd_box->max[d] - smin) / width);
686 
687  POSTGIS_DEBUGF(5, " stats: dim %d: min %g: max %g: width %g", d, smin, smax, width);
688  POSTGIS_DEBUGF(5, " overlap: dim %d: (%d, %d)", d, nd_ibox->min[d], nd_ibox->max[d]);
689 
690  /* Push any out-of range values into range */
691  nd_ibox->min[d] = Max(nd_ibox->min[d], 0);
692  nd_ibox->max[d] = Min(nd_ibox->max[d], size-1);
693  }
694  return true;
695 }
float4 size[ND_DIMS]
int min[ND_DIMS]
N-dimensional box index type.
static char * nd_box_to_json(const ND_BOX *nd_box, int ndims)
Convert an ND_BOX to a JSON string for printing.
float4 max[ND_DIMS]
int max[ND_DIMS]
float4 min[ND_DIMS]
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