Calc Areas

Description

This functor calculates the area of each source feature.

Inputs

Name	Type	Description
Source	Categorical Map	Map whose non-null cells correspond to categories or classes.
Use Authalic Area	Boolean Value	If set to true, the area of each cell in a geographic grid (Lat/Long) is computed using an authalic sphere, which preserves surface area during projection. This improves the accuracy of area calculations across all latitudes by avoiding distortions in geographic coordinate systems. If the grid is geographic but the flag is set to false, all cells are treated as having the same area, calculated by treating the length of one degree of latitude or longitude as a constant 111255 meters.

Output

Name	Type	Description
Areas	Table	Area of each map category in cells, hectares and square meters.

Group

Map Algebra

Notes

Only the areas corresponding to class or categories defined in the input map header are calculated.

If the cell dimensions are represented using degrees, the areas in hectares and square meters becomes an approximation. All cells are always supposed to be of the same size.

The table containing the resulting area has the following format.

Column Name	Key or Data?	Column Type	Description
“Category”	Key	Real	Category in the feature map
“Area_In_Cells”	Data	Real	Area of corresponding category in cells
“Area_In_Hectares”	Data	Real	Area of corresponding category in hectares
“Area_In_Square_Meters”	Data	Real	Area of corresponding category in square meters

Internal Name

CalcAreas