Lol

h2/gift_wrapper.py

@@ -1,7 +1,7 @@
 # Use atan2 instead of acos to calc angle; atan2(x,y) of the point we potentially want to add
 from math import acos, sqrt
 
-from util import Vector, Point, gen_point, display
+from util import Vector, Point, gen_point
 
 
 def calc_angle(v1: Vector, v2: Vector) -> float:
@@ -10,8 +10,7 @@ def calc_angle(v1: Vector, v2: Vector) -> float:
     len_2 = sqrt(v2.x**2 + v2.y**2)
 
     tmp = dot / (len_1 * len_2)
-
-    return acos(round(tmp, 6))
+    return acos(max(min(tmp, 1), -1))  # acos is only defined in [-1,1]
 
 
 def calc_vector(p1: Point, p2: Point) -> Vector:

h2/mbc.py

@@ -1,13 +1,17 @@
+import random
 import statistics
 from math import inf
 from typing import Set, List, Tuple
 
+from scipy.optimize import linprog
+
+import util
 from util import Side, Point, gen_point, display
 
 
-def sidedness(slope: float, intersection: float, p3: Point, linprog_flipper: callable, eps=0.0000001) -> Side:
+def sidedness(slope: float, intersection: float, p3: Point, flipper: callable, eps=0.0000001) -> Side:
     # finds where a point is in regards to a line
-    if linprog_flipper(p3.y) - eps <= linprog_flipper(slope * p3.x + intersection) <= linprog_flipper(p3.y) + eps:
+    if flipper(p3.y) - eps <= flipper(slope * p3.x + intersection) <= flipper(p3.y) + eps:
         return Side.ON
     elif p3.y > slope * p3.x + intersection:
         return Side.ABOVE
@@ -45,17 +49,16 @@ def solve_2dlp(c: Tuple[float, float], constraints: List[Tuple[Tuple[float, floa
     x1, x2 = (-inf, -inf) if c1 > 0 else (inf, inf)
     #random.shuffle(constraints)
 
-    for i, ((a1, a2), b) in enumerate(constraints[1:], start=1):
-        if a1*x1 + a2*x2 <= b:
-            continue
-
-        x1 = solve_1dlp(c1 - c2*a1/a2, [(ai1 - ai2*a1 / a2, bi - ai2*b / a2) for (ai1, ai2), bi in constraints[:i]])
+    for i, ((a1, a2), b) in enumerate(constraints[1:], start=0):
+        if not a1*x1 + a2*x2 <= b:
+            x1 = solve_1dlp(c1 - c2*a1/a2,
+                            [(ai1 - ai2*a1 / a2, bi - ai2*b / a2) for (ai1, ai2), bi in constraints[:i]])
             x2 = (b - a1*x1) / a2
 
     return x1, x2
 
 
-def mbc_ch(points: Set[Point], linprog_flipper: callable) -> Set[Point]:
+def mbc_ch(points: Set[Point], flipper: callable) -> Set[Point]:
     if len(points) <= 2:
         return points
 
@@ -67,26 +70,19 @@ def mbc_ch(points: Set[Point], linprog_flipper: callable) -> Set[Point]:
     pr = {p for p in points if p.x >= med_x}
 
     # Find the bridge over the vertical line in pm
-    c = (linprog_flipper(med_x), linprog_flipper(1))
-    A = [(linprog_flipper(-p.x), linprog_flipper(-1)) for p in points]
-    b = [linprog_flipper(-p.y) for p in points]
-
-    #result = linprog(c, A, b, bounds=[(None, None), (None, None)], options={"tol": 0.00001})
-    #slope, intercept = result.x[0], result.x[1]
-
-    slope, intercept = solve_2dlp(c, list(zip(A, b)))
-
-    #display_line_only(points, slope, intercept, [])
+    slope, intercept = solve_2dlp((flipper(med_x), flipper(1)),
+                                  [((flipper(-p.x), flipper(-1)), flipper(-p.y)) for p in points])
 
     # Find the two points which are on the line, should work
-    left_point = next(p for p in pl if sidedness(slope, intercept, p, linprog_flipper) == Side.ON)
-    right_point = next(p for p in pr if sidedness(slope, intercept, p, linprog_flipper) == Side.ON)
+    on = {p for p in points if sidedness(slope, intercept, p, flipper) == Side.ON}
+    left_point = min(on)
+    right_point = max(on)
 
     # Prune the points between the two line points
-    pl = {p for p in pl if p.x <= left_point.x}
-    pr = {p for p in pr if p.x >= right_point.x}
+    pl = {p for p in points if p.x <= left_point.x}
+    pr = {p for p in points if p.x >= right_point.x}
 
-    return set.union(mbc_ch(pl, linprog_flipper), {left_point, right_point}, mbc_ch(pr, linprog_flipper))
+    return set.union(mbc_ch(pl, flipper), {left_point, right_point}, mbc_ch(pr, flipper))
 
 
 def mbc(points: Set[Point]) -> Set[Point]:

h2/tmptest.py

@@ -7,16 +7,26 @@ from graham import graham_scan
 from mbc import mbc
 from quick_hull import quick_hull
 
-random.seed(1337_420)
+#random.seed(1337_420)
 
-points = {util.gen_point(-100, 100) for i in range(5_000)}
+while True:
+    print("="*100)
+    points = {util.gen_point(-100, 100) for i in range(100)}
+    print("Points:", sorted(points))
 
     # Sanity check
     graham = set(graham_scan(points))
     gift = set(rapper(points))
     quick = quick_hull(points)
     mbch = set.union(mbc(points))
-assert gift == graham == quick == mbch
+
+    print("graham:", sorted(graham))
+    print("gift  :", sorted(gift))
+    print("quick :", sorted(quick))
+    print("mbch  :", sorted(mbch))
+
+    if not gift == graham == quick == mbch:
+        util.display(points=points, hull=mbch)
 
 
 def time_it(f: callable, args: tuple = (), iterations=20):

h2/util.py

@@ -32,7 +32,7 @@ def display(points: Set[Point], hull: Set[Point]):
     plt.show()
 
 
-def display_line_only(points: Set[Point], slope: int, intercept: int, line_points: Set[Point]):
+def display_line_only(points: Set[Point], slope: float, intercept: float, line_points: Set[Point]):
     x = [point.x for point in points]
     y = [point.y for point in points]