euler_numbereuler_numberEulerNumberEulerNumbereuler_number (Operator)
Name
euler_numbereuler_numberEulerNumberEulerNumbereuler_number — Calculate the Euler number.
Signature
def euler_number(regions: HObject) -> Sequence[int]
def euler_number_s(regions: HObject) -> int
Description
The operator euler_numbereuler_numberEulerNumberEulerNumberEulerNumbereuler_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.
Execution Information
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Automatically parallelized on tuple level.
Parameters
RegionsRegionsRegionsRegionsregionsregions (input_object) region(-array) → objectHRegionHObjectHRegionHobject
Region(s) to be examined.
EulerNumberEulerNumberEulerNumberEulerNumbereulerNumbereuler_number (output_control) integer(-array) → HTupleSequence[int]HTupleHtuple (integer) (int / long) (Hlong) (Hlong)
Calculated Euler number.
Result
The operator euler_numbereuler_numberEulerNumberEulerNumberEulerNumbereuler_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>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)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>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)set_system("empty_region_result",<Result>).
If necessary an exception is raised.
Possible Predecessors
thresholdthresholdThresholdThresholdThresholdthreshold,
regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowingregiongrowing,
connectionconnectionConnectionConnectionConnectionconnection
Alternatives
connect_and_holesconnect_and_holesConnectAndHolesConnectAndHolesConnectAndHolesconnect_and_holes
Module
Foundation