Golden section method

main.py

@@ -20,3 +20,28 @@ def bisection_method(a, b, eps):
         else:
             a = c
             fa = fc
+
+def f_golden(x):
+    return (x - 2)**2 + 3
+
+def golden_section_search(a, b, eps):
+    phi = (1 + math.sqrt(5)) / 2.0
+    resphi = 2 - phi
+    c = a + resphi * (b - a)
+    d = b - resphi * (b - a)
+    fc = f_golden(c)
+    fd = f_golden(d)
+
+    while (b - a) > eps:
+        if fc < fd:
+            b = d
+            d = c
+            fd = fc
+            c = a + resphi * (b - a)
+            fc = f_golden(c)
+        else:
+            a = c
+            c = d
+            fc = fd
+            d = b - resphi * (b - a)
+            fd = f_golden(d)