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 combine up to three Grid Overlays with boolean operators and use these overlays as input arguments functions and operators. The list of available functions and operators is given in the chapter below. Combo overlays can also take other combo overlays as input. Another powerful combination is the use of combo overlays with Average Overlays (with or without an average distance).

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	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.

Input overlays and timeframes

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.