moments_points_xld — Geometric moments , , and of contours or polygons treated as point clouds.
moments_points_xld calculates the moments (M20, M02, and M11) of a point cloud given by a contour or a polygon XLD (i.e., the order of the points in the contour or polygon is not taken into account). Therefore, the moments are given by
If the contour or polygon is closed (end point = start point), the end point of the contour or polygon is not taken into account to avoid that it receives twice the weight of the other points.
moments_points_xld should be used if the contour XLD intersects itself or if it is not possible to close the contour using a line from end to start point without self-intersection, because in this case moments_xld does not produce useful results. To test whether the contours or polygons intersect themselves, test_self_intersection_xld can be used.
If more than one contour or polygon is passed, the results are stored in tuples in the same order as the respective contours or polygons in XLD.
Contours or polygons to be examined.
Mixed second order moment.
Second order moment along the row axis.
Second order moment along the column axis.
Let n be the number of points of the contour or polygon. Then the run time is O(n).
moments_points_xld returns 2 (H_MSG_TRUE) if the input is not empty. If the input is empty the behavior can be set via set_system(::'no_object_result',<Result>:). If necessary, an exception is raised.
gen_contours_skeleton_xld, smooth_contours_xld, gen_polygons_xld
moments_xld, moments_any_xld, moments_any_points_xld
moments_any_points_xld, area_center_points_xld, moments_region_2nd, area_center