From 49317cdb6e7ae9d94a8c6d17e6c653639d55e65f Mon Sep 17 00:00:00 2001
From: Eric Wolf <robo-eric@gmx.de>
Date: Wed, 7 Dec 2022 05:38:29 +0100
Subject: [PATCH 1/2] add Polynomial.calculate_horner

This allows to evaluate polynomials more efficiently.
---
 polynomial/core.py                   | 13 +++++++++++++
 tests/test_polynomials_operations.py | 19 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/polynomial/core.py b/polynomial/core.py
index b2617c4..ade127e 100644
--- a/polynomial/core.py
+++ b/polynomial/core.py
@@ -291,6 +291,19 @@ def calculate(self, x):
 
         return sum(ak * (x ** k) for ak, k in self.terms)
 
+    def calculate_horner(self, x):
+        """Calculate the value of the polynomial at a given point
+        using Horner`s method.
+
+        This method is faster than calling calculate for almost all
+        polynomials except monomials but might produce slightly different
+        results when using floats.
+        """
+        result = 0
+        for coeff in self:
+            result = coeff + x * result
+        return result
+
     def __call__(self, x):
         """Calculate the value of the polynomial at a given point."""
         return self.calculate(x)
diff --git a/tests/test_polynomials_operations.py b/tests/test_polynomials_operations.py
index af06f00..1e04578 100644
--- a/tests/test_polynomials_operations.py
+++ b/tests/test_polynomials_operations.py
@@ -1310,6 +1310,25 @@ def test_calculate_zero_polynomial(self):
         self.assertEqual(0, Constant(0).calculate(5))
         self.assertEqual(0, Monomial(0, 1).calculate(1.1))
 
+    def test_calculate_horner(self):
+        """Tests calculate_horner on a simple polynomial."""
+        a = Polynomial(1, 2, 3)
+
+        def eqn(x):
+            return x ** 2 + 2 * x + 3
+
+        for i in range(-100, 100):
+            i = i / 100
+            self.assertAlmostEqual(eqn(i), a.calculate_horner(i))
+
+    def test_calculate_horner_zero_polynomial(self):
+        """Test that calculations of zero polynomial values
+        using Horner`s method always give 0.
+        """
+        self.assertEqual(0, ZeroPolynomial().calculate_horner(1))
+        self.assertEqual(0, Constant(0).calculate_horner(5))
+        self.assertEqual(0, Monomial(0, 1).calculate_horner(1.1))
+
     def test_call(self):
         """Tests calculate on a simple polynomial."""
         a = Polynomial(1, 2, 3)

From c1daa6270992b89c2a3765e532791346fe288dc4 Mon Sep 17 00:00:00 2001
From: Eric Wolf <robo-eric@gmx.de>
Date: Thu, 8 Dec 2022 06:52:07 +0100
Subject: [PATCH 2/2] fix docstring style

---
 polynomial/core.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/polynomial/core.py b/polynomial/core.py
index ade127e..7fbda6f 100644
--- a/polynomial/core.py
+++ b/polynomial/core.py
@@ -292,12 +292,11 @@ def calculate(self, x):
         return sum(ak * (x ** k) for ak, k in self.terms)
 
     def calculate_horner(self, x):
-        """Calculate the value of the polynomial at a given point
-        using Horner`s method.
+        """Calculate the value of the polynomial at a given point.
 
-        This method is faster than calling calculate for almost all
-        polynomials except monomials but might produce slightly different
-        results when using floats.
+        This method is using Horner`s method and faster than calling
+        calculate for almost all polynomials except monomials but might
+        produce slightly different results when using floats.
         """
         result = 0
         for coeff in self: