Calculate Euler number.
The procedure euler_number calculates the Euler number, i.e. the difference between the number of connection components and the number of holes. If more than one region is passed the results are stored in tuples, the index of a value in the tuple corresponding to the index of a region in the input.
Regions (input_object) |
region(-array) -> object |
Region(s) to be examined. |
EulerNumber (output_control) |
integer(-array) -> integer |
Calculated Euler number. |
The operator euler_number returns the value TRUE if the input is not empty. The behavior in case of empty input (no input regions available) is set via the operator set_system(::'no_object_result',<Result>:). The behavior in case of empty region (the region is the empty set) is set via set_system(::'empty_region_result',<Result>:). If necessary an exception is raised.
threshold__, regiongrowing__, connection