Operator Reference

orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldorientation_points_xld (Operator)

orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldorientation_points_xld — Calculate the orientation of contours or polygons treated as point clouds.

Signature

orientation_points_xld(XLD : : : Phi)

Description

The operator orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldorientation_points_xld calculates the orientation PhiPhiPhiphiphi of the point clouds given by the contours or polygons XLDXLDXLDXLDxld (the order of the points in the contour or polygon is not taken into account). The orientation PhiPhiPhiphiphi is calculated the same way as in elliptic_axis_points_xldelliptic_axis_points_xldEllipticAxisPointsXldEllipticAxisPointsXldelliptic_axis_points_xld. 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.

In addition, the contour point with maximum distance to the center of gravity is calculated. If the angle between the vector and the vector given by PhiPhiPhiphiphi is greater than , the value of is added to the angle. If XLDXLDXLDXLDxld consists of only two points, PhiPhiPhiphiphi is given by the direction from the first point towards the second point.

orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldorientation_points_xld should be used if the contour XLDXLDXLDXLDxld 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 orientation_xldorientation_xldOrientationXldOrientationXldorientation_xld does not produce useful results. To test whether the contours or polygons intersect themselves, test_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXldtest_self_intersection_xld can be used.

If more than one contour or polygon is passed, the values of the orientations are stored in a tuple in the same order as the respective contours or polygons in XLDXLDXLDXLDxld.

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

XLDXLDXLDXLDxld (input_object) xld(-array) → object

Contours or polygons to be examined.

PhiPhiPhiphiphi (output_control) angle.rad(-array) → (real)

Orientation of the contours or polygons (radians).

Assertion: - pi < Phi && Phi <= pi

Possible Predecessors

gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXldgen_contours_skeleton_xld, edges_sub_pixedges_sub_pixEdgesSubPixEdgesSubPixedges_sub_pix, threshold_sub_pixthreshold_sub_pixThresholdSubPixThresholdSubPixthreshold_sub_pix, gen_contour_polygon_xldgen_contour_polygon_xldGenContourPolygonXldGenContourPolygonXldgen_contour_polygon_xld

Alternatives

orientation_xldorientation_xldOrientationXldOrientationXldorientation_xld, elliptic_axis_points_xldelliptic_axis_points_xldEllipticAxisPointsXldEllipticAxisPointsXldelliptic_axis_points_xld, smallest_rectangle2_xldsmallest_rectangle2_xldSmallestRectangle2XldSmallestRectangle2Xldsmallest_rectangle2_xld

Module

Foundation

Operators