List of Combo Overlay examples

Attribute

Solid Buildings

The attribute SOLID generally has a value of 0 or 1. It can therefore be used directly in a Combo Overlay Formula.

• Set Combo Maplink to BUILDINGS
• Set Key A to SOLID
• Set Formula to:

  @A

Residential Buildings

The unit size category values can be used to identify and rasterize residences, in combination with a GT (Greater than) function with multiple arguments. To setup:

• Set Combo Rasterization to "Attribute:Specific Layer" (SINGLE_LAYER)
• Set Combo Maplink to Buildings
• Set Key A to SOCIAL_UNIT_SIZE_M2
• Set Key B to NORMAL_UNIT_SIZE_M2
• Set Key C to LUXE_UNIT_SIZE_M2
• Set Key D to STUDENT_UNIT_SIZE_M2
• Set Key E to SENIOR_UNIT_SIZE_M2
• Set Formula to:

  GT(@A,@B,@C,@D,@E)

Categorized Residential Buildings

The unit size category values can be used to identify and rasterize residence types, in combination with a IF and GT (Greater than) functions with multiple arguments. We will categorize the residential buildings as followed: SOCIAL (1) , NORMAL (2), LUXE (3), SENIOR (4), STUDENT (5) and everything else 0.

To setup:

• Set Combo Rasterization to "Attribute:Specific Layer" (SINGLE_LAYER)
• Set Combo Maplink to Buildings
• Set Key A to SOCIAL_UNIT_SIZE_M2
• Set Key B to NORMAL_UNIT_SIZE_M2
• Set Key C to LUXE_UNIT_SIZE_M2
• Set Key D to SENIOR_UNIT_SIZE_M2
• Set Key E to STUDENT_UNIT_SIZE_M2
• Set Formula to:

  IF(GT(@A,0),1,IF(GT(@B,0),2,IF(GT(@C,0),3, IF(GT(@D,0), 4, IF(GT(@E,0),5,0))))

Rasterization

Minimum infiltration among layers

An example on how the combo overlay can obtain rasterized data from multiple data layers (MapLinks); Terrains, Buildings, Neighborhoods, Areas and Zones.

• Set Combo Rasterization to "Attribute:Min value" (MIN)
• Set Combo Maplink to nothing (null)
• Set Key A to GROUND_INFILTRATION_MD
• Set Formula to:

  @A

Timeframes

Minimum value among timeframes

An example on how the Combo Overlay can calculate the minimum value among timeframes of a Prequel Grid Overlay

• Set A prequel (Combo Overlay) to the Grid Overlay (with 10 timeframes).
• Set Formula to:

  MIN(A0:9)

Maximum value among timeframes

An example on how the Combo Overlay can calculate the maximum value among timeframes of a Prequel Grid Overlay

• Set A prequel (Combo Overlay) to the Grid Overlay (with 10 timeframes).
• Set Formula to:

  MAX(A0:9)

Mask for each timeframe

An example on how the Combo Overlay can calculate, for each timeframe of an input overlay, whether a grid value is above a specific value. In this example a Heat Stress Overlay with a minimum value of 45 degrees.

• Set A prequel (Combo Overlay) to a Grid Overlay, in this example a Heat Stress Overlay.
• Set Formula to:

  IF(GT(AT, 45), 1, 0)

Filter each timeframe

An example on how the Combo Overlay can calculate, for each timeframe of an input overlay, only include a grid value when it is above a specific value, and make it NO_DATA otherwise. In this example a Heat Stress Overlay with a minimum value of 45 degrees.

• Set A prequel (Combo Overlay) to a Grid Overlay, in this example a Heat Stress Overlay.
• Set Formula to:

  IF(GT(AT, 45), AT, NO_DATA)

Colors

Grid input to colors

An example on how a combo overlay can return a complex colorization using a grid input without using a legend. This example expects the value of an input Grid Overlay to be:

• Negative or NO_DATA in case it has no direction
• A value between 0 and 360 indicating a direction.

Configure the Combo Overlay as followed:

• Set Grid A to an input overlay representing a direction in degrees, such as Surface avg direction result type (Water Overlay)
• Set Formula to:

  IF(OR(LT(AT, 0), EQ(NO_DATA, AT)), NO_DATA, IF(LT(AT, 15), COLOR(255, 0), IF(LT(AT, 45), COLOR(255, 125, 0), IF(LT(AT, 75), COLOR(255, 255, 0), IF(LT(AT, 105), COLOR(125, 255, 0), IF(LT(AT, 135), COLOR(0, 255, 0), IF(LT(AT, 165), COLOR(0, 255, 125), IF(LT(AT, 195), COLOR(0, 255, 255), IF(LT(AT, 225), COLOR(0, 125, 255), IF(LT(AT, 255), COLOR(0, 0, 255), IF(LT(AT, 285), COLOR(125, 0, 255), IF(LT(AT, 315), COLOR(225, 0, 225), IF(LT(AT, 345), COLOR(225, 0, 125), COLOR(255, 0, 0))))))))))))))

Saturate Satellite Imagery

The satellite imagery colors can be saturated using a saturation approximation function. In this example the factor is set to 0.9.

• Set Grid A to a Satellite Overlay
• Set Formula to:

  COLOR(
   ADD(MUL(-1, 0.9, 
    ADD(MUL(0.2989, RED(A)), MUL(0.587, GREEN(A)), MUL(0.114, BLUE(A)))), MUL(ADD(1, 0.9), RED(A))), 
   ADD(MUL(-1, 0.9, 
    ADD(MUL(0.2989, RED(A)), MUL(0.587, GREEN(A)), MUL(0.114, BLUE(A)))), MUL(ADD(1, 0.9), GREEN(A))), 
   ADD(MUL(-1, 0.9, 
    ADD(MUL(0.2989, RED(A)), MUL(0.587, GREEN(A)), MUL(0.114, BLUE(A)))), MUL(ADD(1, 0.9), BLUE(A)))
  )

See also

• Combo Overlay
• Combo Overlay tutorial