Fix branches.

h2/MBC_carlsen.py

@@ -191,3 +191,4 @@ plt.plot(res_xs, res_ys)
 plt.plot(xs, ys, 'ro')
 plt.show()
 
+ 

h2/mbc.py

@@ -1,21 +1,109 @@
+import random
 import statistics
 from collections import namedtuple
-from typing import List, Set
+from enum import Enum, auto
+from typing import Set
+
+import matplotlib.pyplot as plt
+import numpy as np
+from scipy.optimize import linprog
 
 Point = namedtuple('Point', 'x y')
 
 
-def mbc_ch(points: Set[Point]):
+def gen_point(lower: int, upper: int) -> Point:
+    a = random.uniform(lower, upper)
+    b = random.uniform(lower, upper)
+
+    x_i = random.uniform(lower, upper)
+    p_i = Point(x_i, a * x_i + b)
+    p_i = Point(a, b)
+    return p_i
+
+
+def display(points: Set[Point], hull: Set[Point]):
+    x = [point.x for point in points]
+    y = [point.y for point in points]
+
+    h_x = [point.x for point in hull]
+    h_y = [point.y for point in hull]
+
+    plt.plot(h_x, h_y, 'ro')
+
+    plt.scatter(x, y)
+    plt.show()
+
+
+def display_line_only(points: Set[Point], slope: int, intercept: int, line_points: Set[Point]):
+    x = [point.x for point in points]
+    y = [point.y for point in points]
+
+    plt.scatter(x, y)
+
+    # Plot a line from slope and intercept
+    axes = plt.gca()
+    x_vals = np.array(axes.get_xlim())
+    y_vals = intercept + slope * x_vals
+
+    for point in line_points:
+        plt.plot(point.x, point.y, 'go')
+
+    plt.plot(x_vals, y_vals, '--')
+
+    plt.show()
+
+
+class Side(Enum):
+    ON = auto()
+    ABOVE = auto()
+    BELOW = auto()
+
+
+def sidedness(slope: int, intersection: int, p3: Point, linprog_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:
+        return Side.ON
+    elif p3.y > slope * p3.x + intersection:
+        return Side.ABOVE
+    return Side.BELOW
+
+
+def mbc_ch(points: Set[Point], linprog_flipper: callable) -> Set[Point]:
+    if len(points) <= 2:
+        return points
+
     # Find the point with median x-coordinate, and partition the points on this point
-    pm = statistics.median_high(points)
+    med_x = statistics.median(p.x for p in points)
 
-    pl = {point
-          for point in points
-          if point.x < pm.x}
-
-    pr = {point
-          for point in points
-          if point.x >= pm.x}
+    # Find left and right points in regards to median
+    pl = {p for p in points if p.x < med_x}
+    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]
+
+    # 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)
+
+
+
+
+    # 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}
+
+    return set.union(mbc_ch(pl, linprog_flipper), {left_point, right_point}, mbc_ch(pr, linprog_flipper))
+
+
+points = {gen_point(1, 10) for _ in range(20)}
+
+upper_hull_points = mbc_ch(points, lambda x: x)
+lower_hull_points = mbc_ch(points, lambda x: -x)
+
+display(points, upper_hull_points.union(lower_hull_points))