Combo Overlay

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A Combo Overlay, combining a Rainfall Overlay with two Average Overlays (NORMAL and SOCIAL), using only the highest values in the last time frame.

The Combo Overlay is a Grid Overlay which can be used to create additional spatial calculation models. Up to three input Overlays can be selected which serve as input for the calculations. A large set of functions and operators are available which can then perform the desired computations.

Combo Overlays can take any Grid Overlay as input. It is often combined with one or more Average Overlays or Travel Distance Overlays. The Combo Overlay can also use the results of more complex calculation models, such as the Water Overlay or the Heat Overlay to further process the computed results of those models. Finally, Combo Overlays can also refer to other Combo Overlays, to create even more powerful, varied, and complex spatial calculation models.


In the table below are the operators displayed that are supported by the combo overlay. The term argument refers to a grid overlay configured as input, a numerical value or a global name.


  • Up to ten Overlays can be configured as input for the Combo Overlay. These prequels are referenced as A, B, C, etc.
  • You can use Globals in a formula.


When an input Overlay has multiple Timeframes, additional syntax is available to specify the intended timeframes.

Timeframes are 0-indexed, meaning they start counting at 0. The first timeframe is 0, the second timeframe is 1, the tenth timeframe is 9, etc.

Syntax Meaning Example Effect
A The (last) value from Overlay A MUL(A, 10) Assuming:

Will show the height of the water at the end of the calculation in cm (rather than m).

A2 The third timeframe's value from Overlay A GT(A2, 38) Assuming:

Will indicate whether any given location is (1) or is not (0) hotter than 38 °C, on the third computed timeframe of the Heat Overlay.

A0:2 The values from the first through third timeframes from Overlay A, as a list of inputs AVG(A0:2) Assuming:

Will show the average of the computed temperatures of the first three timeframes of the Heat Overlay.

AT For each timeframe of the Combo Overlay, the value from that same timeframe from Overlay A, as individual inputs.

This will cause the Combo Overlay to have at least as many timeframes as Overlay A.

MUL(AT, 10) Assuming:

Will show the height of the water at each timeframe of the Water Overlay's calculations in cm (rather than m).

A Combo Overlay automatically computes the amount of timeframes it requires, based on the following:

  • The amount of timeframes of Input Overlays which are referenced in the formula using the T syntax.
  • The amount of values in Globals which are referenced in the formula. (Globals are automatically interpreted as a Global array.)

The highest found value among all those dictates the amount of Timeframes the Combo Overlay has.


Example of the Combo overlay for bat routes in the Tygron Platform. (In Dutch)
Combining geo-information into a bat network in the Tygron Platform. (In Dutch)


  • When multiple input Overlays are referenced with a "T" syntax and those have varying amounts of timeframes, the maximum amount of timeframes among those input Overlays is used.
  • When the "T" syntax is used to refer to an input Overlay with fewer timeframes than the Combo Overlay itself, any timeframe referenced via the "T" syntax beyond what the input Overlay offers uses whichever value the last timeframe of that input Overlay had. I.e. if a Water Overlay has 10 timeframes but the Combo Overlay attempts to compute an 11th timeframe and beyond, the value from the last (10th) timeframe of the Water Overlay is used.



Example of the Combo overlay in the Tygron Platform. (In Dutch)
Testing a parametric design on environmental criteria in the Tygron Platform. (In Dutch)