Tables in the surface model

The Visum surface model consists of the following seven tables. In these tables, the surfaces of all network objects are displayed. The tables are explained with the aid of an example.

  • Point
  • Edge
  • Edge item
  • Face
  • Face item
  • Surface
  • Surface item

Note: In Visum, you can save polygons together with the network object type using them to a network file (User Manual: Opening and saving a network file and adding comments). However, thereby all polygons are saved, independent of whether they were used for an object of the type specified or not.

Example

In the following example, the seven tables are displayed and explained for a network that contains three main nodes with surfaces.

The network includes the three main nodes with the IDs 2, 3 and 4. These main nodes are allocated via the SurfaceID attribute to the surfaces with the IDs 866, 867 and 868 (Table 29).

Table 29: Table Main nodes

* Table: Main nodes
$MAINNODE:NO;SURFACEID
2;866
3;867
4;868

In the Surfaces table, all surfaces contained in the network are stored with their IDs. Since, in the example, only the three main nodes have a surface, there are exactly three entries for the main node surfaces in this instance (Table 30).

Table 30: Table Surfaces

* Table: Surfaces
$SURFACE:ID
866
867
868

Each surface is composed of one or multiple faces. The allocation of surfaces to faces is carried out in table Surface items. In the example, the surfaces 866 and 868 have exactly one face, whereas surface 869 has two faces. Thus, there are four faces in total with the IDs 1139, 1141, 1144 and 1145 (Table 31).

Table 31: Table Surface items

* Table: Surface items
$SURFACEITEM:SURFACEID;FACEID;ENCLAVE
866;1139;0
868;1141;0
869;1144;0
869;1145;0

In the Faces table, all faces contained in the network are stored with their IDs. In this example, there are thus four faces (Table 32).

Table 32: Table Faces

* Table: Faces
$FACE:ID
1139
1141
1144
1145

In the Face items table, each face is allocated the IDs of the edges which define the face. As you can see in Table 33, the faces with the IDs 1141, 1144 and 1145 are squares each, as they are defined by four edges. Face 1139 however, is a pentagon with five edges.

Table 33: Table Face items

* Table: Face items
$FACEITEM:FACEID;INDEX;EDGEID;DIRECTION
1139;1;33136;0
1139;2;33137;0
1139;3;33138;0
1139;4;33139;0
1139;5;33140;0
1141;1;33145;0
1141;2;33146;0
1141;3;33147;0
1141;4;33148;0
1144;1;33160;0
1144;2;33161;0
1144;3;33162;0
1144;4;33163;0
1145;1;33164;0
1145;2;33165;0
1145;3;33166;0
1145;4;33167;0

The table Edges contains all edges which are required for the description of the face items. Each edge is defined by a start point and an end point, which bear the attribute names FromPointID and ToPointID in the table (Table 34).

Table 34: Table Edges

* Table: Edges
$EDGE:ID;FROMPOINTID;TOPOINTID
33136;9449;9450
33137;9450;9451
33138;9451;9452
33139;9452;9453
33140;9453;9449
33145;9458;9459
33146;9459;9460
33147;9460;9461
33148;9461;9458
33160;9473;9474
33161;9474;9475
33162;9475;9476
33163;9476;9473
33164;9477;9478
33165;9478;9479
33166;9479;9480
33167;9480;9477

In the Points table, all points are displayed which in turn define the edges. Each one contains information on the coordinates (XCoord and YCoord). This establishes the spatial reference of the surface to the network (Table 35).

Table 35: Table Points

* Table: Points
$POINT:ID;XCOORD;YCOORD
9449;3456991.5413;5430055.0204
9450;3456991.5413;5430004.3885
9451;3457052.3873;5429991.7699
9452;3457070.0872;5430048.9542
9453;3457026.8560;5430057.9988
9458;3458808.0227;5431086.8027
9459;3458821.3171;5431061.4225
9460;3458848.5102;5431078.9469
9461;3458835.5180;5431101.9100
9473;3456956.4483;5430005.5296
9474;3456948.8422;5430060.3735
9475;3456887.1928;5430052.7674
9476;3456903.2057;5429996.7225
9477;3456896.8005;5430097.6033
9478;3456938.0336;5430071.1821
9479;3456961.6525;5430097.6033
9480;3456945.2393;5430125.2254

No intermediate points were generated in the example. The table is therefore empty (Table 36).

Table 36: Table Intermediate points

* Table: Intermediate points
$EDGEITEM:EDGEID;INDEX;XCOORD;YCOORD