Dist

Geometric functions dist(ance)

syntax

• dist(destination, origin)

definition

dist(destination, origin) calculates the distance (as the crow flies) between origin and destination points of the same Domain unit.

The resulting Data item has a float32 Value type without Metric. Use the Value function to convert the result to the requested Values unit.

description

Use the Sqrdist function if only the distance order is relevant as the sqrdist function calculates faster.

applies to

• destination and origin are data items with Point value type

conditions

The values unit and domain unit of the destination and origin arguments must match.

example

attribute<meter> distOD (ADomain) := value(dist(destination, origin), meter);

destination	origin	distOD
{401331, 115135}	{401331, 115135}	0
{399501, 111793}	{399476, 111803}	26.9
{399339, 114883}	{399289, 114903}	53.9
{401804, 111323}	{401729, 111353}	80.8
{398796, 111701}	{398696, 111741}	107.7

ADomain, nr of rows = 5

see also

• Sqrdist

extra: distance between points of different domains

If you want to calculate the distance to the nearest point between two different domains, the following example script can be used.

unit<uint32> from_domain  := plan 
{
   attribute<rdc_meter> geometry      := plan/geometry;
   attribute<to_domain> to_domain_rel := connect(to_domain/geometry, geometry);
   attribute<rdc_meter> geometry_to   := to_domain/geometry[to_domain_rel];

   attribute<meter> dist              := value(dist(geometry_to, geometry), meter);
}

unit<uint32> to_domain  := city
{
   attribute<rdc_meter> geometry := city/geometry;
}