Using the Split function, you can subdivide zones into smaller units. The number of rows and columns of a matrix is changed through splitting. This function is often used for adapting overall demand matrices to a finer zone classification in the network model.
- If you only specify one factor for an object generated during splitting, this factor applies to both the source and destination traffic in the demand matrix.
- If origin and destination value are to be distributed with different proportions in a zone generated by splitting, a destination traffic factor must also be specified after the origin traffic factor.
For a demand matrix, the matrix value is generally distributed across the zones (1.0 = 100 %) created through splitting. When choosing the splitting factors for zone generation, you can decide whether or not you want to include the expected gains (total > 1.0) or losses (total < 1.0) per split zone.
For a skim matrix, the matrix value per split zone is generally assigned to the new zones using the factor 1.0, i.e. they remain unchanged.
Example of splitting matrix objects
The zones of the following matrices are split and deleted.
Thereby the following settings are made:
|
Zone number old |
Zone number new |
Factor origin traffic |
Factor destination traffic |
|
100 |
1001 |
0.3 |
0.1 |
|
100 |
1002 |
0.5 |
0.2 |
|
100 |
1003 |
0.2 |
0.7 |
|
200 |
2001 |
0.7 |
0.7 |
|
200 |
2002 |
0.3 |
0.3 |
In addition, all trips created within the cell are set to null.
This produces the following matrix:
Total of matrix data for all OD pairs from/to 1,001..1.,003 equals 1,000.
