euler_number — Calculate the Euler number.
euler_number(Regions : : : EulerNumber)
The operator euler_number calculates the Euler number, i.e., the
difference between the number of connection components and the number of
holes.
In the documentation of this chapter (Regions / Features), you can find an image illustrating regions which vary in their Euler number.
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 2 (H_MSG_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
Foundation