Combo Overlay

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 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.

Operators

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.

Name	Arguments	Type	Displays
SIN	Single		Sine function
COS	Single		Cosine function
TAN	Single		Tangent function
ASIN	Single		Arc sine function
ACOS	Single		Arc cosine function
ATAN	Single		Arc tangent function
ROUND	Single		Round function
FLOOR	Single		Floor function
CEIL	Single		Ceil function
ABS	Single		Absolute function
EXP	Single		Exponential function
LN	Single		The natural logarithm (base e) function
LOG	Single		The natural logarithm (base 10) function
SQRT	Single		The square root function
RANDOM	Single		The random function, which returns a number greater than or equal to 0.0 and less than the provided argument
ERF	Single		The gauss error function, for probability calculations.
ADD	Multi		Add one or more argument
MULT	Multi		Multiply one or more arguments
SUB	Multi		Subtract one or more arguments from the first argument
DIV	Multi		Divide the first argument with one or more other arguments
MIN	Multi		Returns the smallest of the provided arguments. That is, the result is the argument closest to negative infinity.
MAX	Multi		Returns the largest of the provided arguments. That is, the result is the argument closest to positive infinity.
POW	Multi		Raises the first argument to the power of the consecutive arguments. For example 2 to the power 3 to the power 4.
IF	Multi		Takes 3 arguments. If first argument is exactly 1, returns the second argument, else return the third argument.
OR	Multi		Returns 1.0 if any argument is not equal to 0.0.
AND	Multi		Returns 1.0 if all arguments are not equal to 0.0.
GTE	Pair		Returns 1.0 if the first argument is larger than or equal to the second argument, else returns 0.0.
GT	Pair		Returns 1.0 if the first argument is larger than the second argument, else returns 0.0.
LTE	Pair		Returns 1.0 if the first argument is smaller than or equal to the second argument, else returns 0.0.
LT	Pair		Returns 1.0 if the first argument is smaller than the second argument, else returns 0.0.
NEQ	Pair		Returns 1.0 if the first argument is not equal to the second argument, else returns 0.0.
EQ	Pair		Returns 1.0 if the first argument is equal to second argument, else returns 0.0.
NO_DATA	Constant		The NO_DATA value for grid data, indicating no data exists.

Inputs

• Up to three overlays can be configured as input for the combo overlay. They are referenced as A, B and C.
• You can use Globals in a formula.

Timeframes

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

Syntax	Meaning	Example	Effect
A	The (last) value from Overlay A	MUL(A, 10)	Assuming: A is a Water Overlay with Surface Last Value as result type 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: A is a Heat Overlay with Physiological Equivalent Temperature as result type 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: A is a Heat Overlay with Physiological Equivalent Temperature as result type 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: A is a Water Overlay with Surface Last Value as result type 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 whether (and which of) its input Overlays are references with a "T" syntax.

Examples

• Combo Overlay with average overlays
• Combo Overlay with masking
• Combo Overlay with distance filtering

Notes

• 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.

How-to's

• How to add and remove an Overlay
• How to edit a Combo Overlay's formula
• How to edit an overlay legend
• How to add and remove an Attribute

Videos

Example of the Combo overlay in the Tygron Platform. (In dutch)

Testing a parametric design on environmental criteria in the Tygron Platform. (In dutch)

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Overlays

Categorization

Grid • Parent • Result Child • Result Parent • Result type

Default

City

Administrative

Ownership • Ownership Grid • Zipcodes • Zoning • Neighborhoods • Municipalities • Vacancy

Environmental

Heat Stress • Traffic Density • Traffic Noise • Traffic NO2 • Livability • Aerius

Water

Rainfall • Flooding • Groundwater • Subsidence • Watershed • Waterwijzer

Raster Calculation

Average • Combo • Distance • Sight Distance • Travel Distance

Geo Data

Area • Attribute • GeoTIFF • WCS • WMS • Image

Topography

Digital Surface Model • Digital Terrain Model • Underground • Function • Source

Network

Network Distance • Network Overview • Network Ownership