Combo Overlay with masking

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

Use Case Description

How can I 'mask' (filter out) all values of a rainfall overlay that is not of the highest range? In this case we use the default highest range of 50 cm or more.

For this we need to add a rainfall overlay and a formula we can use to mask the values that are too low.

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  Rainfall overlay

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  Combo Overlay with masking

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