With the help of this function you can adjust the demand matrix of a PrT demand segment to the count data gained from several links (Fundamentals: Projecting PrT path volumes).
1. Make sure that the counted volumes are provided as AddValue data of links (Links: Basis tab).
2. Make sure, that the network contains a PrT assignment result (routes via this link) and counted link data or a random sampling factor.
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Note: The function PrT paths projection cannot be used with a PrT assignment of the variant Equilibrium assignment LUCE. |
3. On the Demand menu, click Paths projection.
The Graphics tools (Paths projection) window opens.
4. Make the desired changes.
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Element |
Description |
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Demand segment PrT |
Via the selection list you may pick the PrT demand segment, whose route volumes you would like to project. |
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Count data from |
Via the selection list you may pick the Link-AddValue that is coding the census data. |
5. Mark the desired link (Selecting links).
In the Tools (Paths projection) window, the Number, the number of the From-node, the Volume and the Counted value of the marked link are displayed and the Factor (= Counted value divided by PrT link volume), which is automatically calculated.
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Note: The factor is calculated each time a new link is marked. |
6. If necessary, edit the projection factor.
7. If necessary, mark the reverse direction of the link: Click the Direction: Down button.
8. Click the Execute button.
All OD pairs of the demand matrix that use the marked link are recalculated with the projection factor calculated for this link. The route volumes are adjusted.
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Note: Rounding errors might cause deviations of the rounded result (for example 2 • 1.3 trips = 2.6 trips is rounded to 3 trips). |
9. Mark further links, if necessary, and project the OD pairs using these links.
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Tip: You can display all OD pairs which use the selected or the projected link as flow bundle via the menu Graphics > Flow bundle (Spinne einfügen). |
