Rounding demand and volume data

You may specify that demand data and volumes have to be rounded.

Notes: This setting is regarded by any procedure using demand data and has to be set prior to reading the demand matrix from file.

This setting neither affects skim matrix calculations nor zone lists or overall statistics. For these output values, the exact non-rounded demand and path volumes are always used.

1. From the Calculate menu, choose General procedure settings.

The General procedure settings window opens.

2. In the navigator, select PuT settings > Assignment.

3. Make the desired settings.

Element	Description
Round demand and volume data	If this option has been checked, the demand values will be rounded to the specified Number of decimal places. The volumes of all paths will be of the same precision. If this option has not been checked, the original values are used for the calculation. Notes Due to the precise calculation more paths are stored, i.e. the memory requirements for the assignment result rise with the calculation accuracy. In case of large networks, we recommend to make use of the rounding option. If reasonable in terms of memory requirements, the exact real-valued volume should always be used in order to obtain the most precise calculation results. In the case of demand matrices with sparsely filled OD pair data it is recommended to activate the rounding option since the program might discard more paths than desired if the rounding is too coarse. When reading older version files or PuT connection files, the option is always checked. Within a capacity-restricted assignment, even when vehicle sharing systems are taken into account, the volumes values of the connections are rounded only in the last iteration. Number of decimal places If the option has been checked, you can set the number of decimal places to which you want to round in the input field. Values from 0-20 are permitted. Multiples of If the option has been checked, the value is rounded up or down so that the new value is a multiple of the value specified for rounding (Example: “Round to a multiple of”).

Element

Description

Round demand and volume data

If this option has been checked, the demand values will be rounded to the specified Number of decimal places. The volumes of all paths will be of the same precision.

If this option has not been checked, the original values are used for the calculation.

Notes

Due to the precise calculation more paths are stored, i.e. the memory requirements for the assignment result rise with the calculation accuracy. In case of large networks, we recommend to make use of the rounding option. If reasonable in terms of memory requirements, the exact real-valued volume should always be used in order to obtain the most precise calculation results.

In the case of demand matrices with sparsely filled OD pair data it is recommended to activate the rounding option since the program might discard more paths than desired if the rounding is too coarse.

When reading older version files or PuT connection files, the option is always checked.

Within a capacity-restricted assignment, even when vehicle sharing systems are taken into account, the volumes values of the connections are rounded only in the last iteration.

Number of decimal places

If the option has been checked, you can set the number of decimal places to which you want to round in the input field. Values from 0-20 are permitted.

Multiples of

If the option has been checked, the value is rounded up or down so that the new value is a multiple of the value specified for rounding (Example: “Round to a multiple of”).

4. Confirm with OK.

The changes are applied. The next PuT assignment will use the new settings.