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Edit a distance matrix

The Modelling Environment tool allows a user to create and edit ‘Distance Matrices’ for each variable that can be used in the cluster tool. This matrix can be thought of as similar to the mileage gazetteers found in the back of road atlases and tells the clustering tool how close (or similar) each category of a nominal variable is to every other one. Matrices can be entered by hand or initially generated from a profile result.

  1. From the Dimensions tab right click on the variable you want to create/edit a ‘Distance Matrix’ for

  2. From the pop up window select the option Edit Distance Matrix

Matrix types

  • Nominal: Where there is no natural relationship between the categories. Each cell between the same categories is set to 0 (no difference, along the diagonal) and between any pair of different categories is set to a value of 1 (maximum difference)

    • Ordinal: Where there is a calculable difference between the categories. Each cell between the same categories (on the diagonal) is set to 0, and between other category pairs is set to the number of steps away they are from each other (e.g. <£10k is 2 steps away from £20-30k)

    • Custom: Where you have manually edited the grid with values you have determined externally

    • Custom-PWE: Where you have applied values that have been calculated from a Profile within the Modelling Environment. Each cell contains the difference in PWE value for the 2 categories