This function allows you to group several matrix objects to create one or several new objects. You can use the Aggregate function to rename zones and/or group them into larger units (e.g. districts). The number of rows and columns of a matrix is changed through aggregation.
The new matrix values are calculated with the aid of the following formulas:
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Arithmetic mean |
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Weighted mean |
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with
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qi |
Matrix value of ith zone |
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gi |
Weighting of ith zone |
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n |
Number of columns or rows |
Example of aggregating matrix objects
The matrix values of the matrix below are aggregated.
Zone allocations and settings:
- Zone 10 is removed from the matrix
- Zones 20 and 30 are aggregated and will form the new zone 39
- The weighted mean is used as aggregate function.
- The matrix data is weighted using the following matrix.
- Origin and destination zones of the matrix are aggregated
- The matrix values of the original matrix are used
The following matrix results.
Matrix values of destination zone 39 were calculated as follows:
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Note: If you aggregate a filtered matrix, only the filtered values are aggregated. |
