You can configure certain settings for the calculation of PrT (Fundamentals: PrT skims) and PuT (Fundamentals: PuT skims) skim matrices. The settings of PuT apply to the calculation of stop area skim matrices. For path sequence paths, you can specify separate skims and calculate skim matrices.
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Note: Skim matrices can be generated with the procedures Calculate PrT skim matrix (Calculating PrT skims), Calculate PuT skim matrix (Calculating PuT skims), Calculate stop area skim matrix (Calculating stop area skim matrices), and Calculate skim matrix from path sequences(Calculating demand from path sequences). For PuT, you may additionally calculate and save skim matrices simultaneously with an assignment (Calculating skim matrices during an assignment). |
1. From the Calculate menu, choose General procedure settings.
The General procedure settings window opens.
2. In the navigator, select the desired entry.
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Entry |
Description |
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PrT settings > Skims |
On this page, you set metadata for PrT skim matrices. Each row contains the settings for a specific PrT skim matrix type. |
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PuT settings > Skims |
On this page, you set metadata for PuT skim matrices. Each row contains the settings for a specific PuT skim matrix type. |
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Skims for path sequences |
On this page, you set metadata for skim matrices for path sequences. Each column contains the settings for a specific skim matrix type. You can specify the skims yourself. |
3. For the desired matrix type, edit the desired entry in the particular column or row. For skim matrices for path sequences, you need to create the skims beforehand (Specifying skims for path sequences).
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Element |
Description |
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Skim |
Name of the skim The entries are not subject to changes. |
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Code / file extension |
Standard code / file extension of the output file Note Please note that renaming may cause identification problems, since the manual and PTV Vision Support refer to standard file extensions. |
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Diagonal |
Via this button, you set the value for the main diagonal by matrix type. The button labels indicate the current settings (Specifying main diagonal values of a matrix type). |
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Ignored OD pair value |
Standard entry for OD pairs which according to the filter settings are not taken into account for skim matrix calculation |
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No paths found value |
Standard entry for OD pairs for which no path could be found |
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Minimum value |
Minimum permitted value. This value will be used instead of smaller calculated values. |
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Maximum value |
Maximum permitted value. This value will be used instead of greater calculated values. |
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Decimal places |
Number of decimal places (0 – 9) |
4. Confirm with OK.
The changes are applied.
Specifying main diagonal values of a matrix type
1. From the Calculate menu, choose General procedure settings.
The General procedure settings window opens.
2. In the navigator, select the desired entry.
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Entry |
Description |
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PrT settings > Skims |
On this page, you set metadata for PrT skim matrices. Each row contains the settings for a specific skim matrix type. |
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PuT settings > Skims |
On this page, you set metadata for PuT skim matrices. Each row contains the settings for a specific skim matrix type. |
3. In the desired row, click the button in the Diagonal column.
The Set main diagonal for skim <matrix type> window opens.
4. Make the desired changes.
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Element |
Description |
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With constant value |
If this option has been checked, the constant value entered here is applied to the cells of the main diagonal. |
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From attribute |
If this option has been checked, the numerical zone attribute which is to be selected via the button is applied to the cells of the main diagonal. |
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Row/column minimum |
If this option has been checked, the minimum value to be found in the corresponding row and column is applied to each cell of the main diagonal. |
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Mean value of n row/column minima |
If this option has been checked, the mean value calculated from other values of the zone is applied to each cell of the main diagonal. For a zone X, the value is calculated as follows: In a first step, the mean values are calculated from the two values each between zone X and any other zone J (vxj and vjx). Then, the mean value calculated from the n smallest values of those mean values is used as value in the main diagonal. |
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n |
Number of values for mean value calculation Note The number needs to be ≥ 1 and may not reach the number of zones. |
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Factor |
Multiplication factor for all values in the main diagonal |
5. Confirm with OK.
The settings for the main diagonal of this matrix type are changed.
