EulerTracker(array[, predicate = identity])

Create an instance of EulerTracker structure.

EulerTracker is a subtype of Abstractarray which wraps over array and allows for fast recalculationg of Euler characteristic when array is changed.

An optional predicate may be specified which is applied to the array before calculation of Euler characteristic.

euler_characteristic(array :: AbstractArray{Bool})

Calculate Euler characteristic for a set of points S on a regular cubic or square grid. The points are defined by a binary array array in such a manner that if array[idx] == true then idx ∈ S.

euler_characteristic(tracker :: EulerTracker)

Return Euler characteristic of the array tracked by tracker.