From 01eda97ff64ad2570b7105cc5b734f488ce0d47a Mon Sep 17 00:00:00 2001
From: Hong-Phuc Bui <hong-phuc.bui@htwsaar.de>
Date: Wed, 04 Jun 2025 18:30:14 +0200
Subject: [PATCH] Implement plus operator
---
polymonial/polynomial.py | 34 ++++++++++++++++
.gitignore | 2 +
polymonial/polynomial_test.py | 25 +++++++++++-
3 files changed, 58 insertions(+), 3 deletions(-)
diff --git a/.gitignore b/.gitignore
index b22ec92..e8153cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
.idea/
__pycache__/
+.coverage
+htmlcov/
diff --git a/polymonial/polynomial.py b/polymonial/polynomial.py
index b847224..2ca4f73 100644
--- a/polymonial/polynomial.py
+++ b/polymonial/polynomial.py
@@ -1,7 +1,11 @@
class Polynomial:
def __init__(self, *argv: float):
+ if len(argv) < 1:
+ raise ValueError("A Polynomial has at least one coefficient.")
+ if argv[-1] == 0:
+ raise ValueError("The coefficient at the highest degree must not be zero.")
self.__coefficients = tuple(argv)
-
+ self.__order = len(argv)
def evaluate(self, x: float) -> tuple[float, list[float]]:
p = self.__coefficients[-1]
@@ -11,8 +15,36 @@
c.insert(0, p)
return c[0], c[1:]
+ def order(self):
+ return self.__order
+
+ def __add__(self, other: "Polynomial") -> "Polynomial":
+ if not isinstance(other, Polynomial):
+ raise ValueError("Operator + is only applicable for Polynomial.")
+ coefficients = []
+ if self.__order > other.__order:
+ low_order = other.__order
+ heigh_order = self.__order
+ higher_coefficients = self.__coefficients
+ else:
+ low_order = self.__order
+ heigh_order = other.__order
+ higher_coefficients = other.__coefficients
+
+ for i in range(0, low_order):
+ coefficients.append(self.__coefficients[i] + other.__coefficients[i])
+ for j in range(i+1, heigh_order):
+ coefficients.append(higher_coefficients[j])
+ return Polynomial(*coefficients)
+
+ def __getitem__(self, key):
+ return self.__coefficients[key]
+
+
def __repr__(self) -> str:
coe = []
for c in self.__coefficients:
coe.append(f'{c}')
return ' '.join(coe)
+
+
diff --git a/polymonial/polynomial_test.py b/polymonial/polynomial_test.py
index f232260..2fa1f53 100644
--- a/polymonial/polynomial_test.py
+++ b/polymonial/polynomial_test.py
@@ -7,12 +7,14 @@
s = str(c)
print(r, s, c)
+
def test_evaluate():
l = Polynomial(-12.5, 3.6)
x = 0.0
(y, rest) = l.evaluate(x)
assert abs(y + 12.5) < EPSILON
+
def test_evaluate_2():
l = Polynomial(11, 7, -5, -4, 2)
x = 2
@@ -23,8 +25,27 @@
assert abs(y - y_expected) < EPSILON
for (i, r) in enumerate( q_expected ):
assert abs(r - q[i]) < EPSILON
- print(Polynomial(*q))
+
+
+def test_polynomial_add():
+ p = Polynomial(-3, 4.5, 6) # ~$p(x) = -3 + 4.5x + 6x^2$~
+ q = Polynomial( 1, 0, 3, -4) # ~$q(x) = 1 + 3x^2 - 4x^3$~
+ s = p + q # ~$s(x) = -2 + 4.5x + 9x^2 - 4x^3$~
+ expected = [-2, 4.5, 9, -4]
+ for (i, ec) in enumerate( expected ):
+ pc = s[i]
+ assert abs(pc - ec) < EPSILON
+
+def test_polynomial_add_2():
+ p = Polynomial(1, 0, 3, -4) # ~$q(x) = 1 + 3x^2 - 4x^3$~
+ q = Polynomial(-3, 4.5, 6) # ~$p(x) = -3 + 4.5x + 6x^2$~
+ s = p + q # ~$s(x) = -2 + 4.5x + 9x^2 - 4x^3$~
+ expected = [-2, 4.5, 9, -4]
+ for (i, ec) in enumerate( expected ):
+ pc = s[i]
+ assert abs(pc - ec) < EPSILON
+
if __name__ == "__main__":
#test_evaluate_2()
- test_polynomial_representation()
\ No newline at end of file
+ test_polynomial_add()
\ No newline at end of file
--
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