increment 1

arithmetic_analysis/bisection.py

@@ -0,0 +1,33 @@
+import math
+
+
+def bisection(function, a, b):  # finds where the function becomes 0 in [a,b] using bolzano
+
+    start = a
+    end = b
+    if function(a) == 0:  # one of the a or b is a root for the function
+        return a
+    elif function(b) == 0:
+        return b
+    elif function(a) * function(b) > 0:  # if none of these are root and they are both positive or negative,
+        # then his algorithm can't find the root
+        print("couldn't find root in [a,b]")
+        return
+    else:
+        mid = (start + end) / 2
+        while abs(start - mid) > 0.0000001:  # until we achieve precise equals to 10^-7
+            if function(mid) == 0:
+                return mid
+            elif function(mid) * function(start) < 0:
+                end = mid
+            else:
+                start = mid
+            mid = (start + end) / 2
+        return mid
+
+
+def f(x):
+    return math.pow(x, 3) - 2*x - 5
+
+
+print(bisection(f, 1, 1000))