Combo Overlay with average overlays

This page describes a use case for implementing a combo overlay.

Use Case Description

In an area, the locations for a clinic, a school and a sports center are known. Which area is for all three locations within a one kilometer range?

For this we would need to combine three average grid overlays, one for each location. then we would need to combine these three ranges in a new combo overlay, linking all three AVG overlays with a formula.

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  Average Overlay Clinic

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  Average Overlay School

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  Average Overlay Sports center

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  Combo Overlay with features

Formula

As we want to indicate the and combine the area that is within the range of all three buildings, the formula for the use case, based on the operators table on the combo overlay page, looks like this:

MIN(A, B, C)

Where A, B and C are the average grid overlays.

How to

How to add a Combo Overlay with features:

1. Give each building or area you want to include a specific attribute (ex: 'FOO', 'BAR', 'BOO',...)
2. Create three Average Overlays, set the cell averaging distance to the desired range
3. Add a Combo Overlay and select the Average overlays in each slot (A,B and C)
4. Enter the formula in the Formula field
5. Select 'Update Now' in case auto-update was disabled

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  Select Distance Sight Overlay

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  Select Legend tab

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  Select "Has Custom Legend"

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  Add new entry

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  Edit the name, value and color of the entry