From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 23 Jul 2019 03:31:44 +0000 (-0400)
Subject: eja: use the @cached_method decorator for characteristic_polynomial().
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=3d7151570d57d56b6e19a3522d6415ed29a3b0d9;p=sage.d.git

eja: use the @cached_method decorator for characteristic_polynomial().
---

diff --git a/mjo/eja/euclidean_jordan_algebra.py b/mjo/eja/euclidean_jordan_algebra.py
index 2c496cd..4fb5f9b 100644
--- a/mjo/eja/euclidean_jordan_algebra.py
+++ b/mjo/eja/euclidean_jordan_algebra.py
@@ -69,7 +69,6 @@ class FiniteDimensionalEuclideanJordanAlgebra(FiniteDimensionalAlgebra):
             True
 
         """
-        self._charpoly = None # for caching
         self._rank = rank
         self._natural_basis = natural_basis
         self._multiplication_table = mult_table
@@ -89,6 +88,7 @@ class FiniteDimensionalEuclideanJordanAlgebra(FiniteDimensionalAlgebra):
 
 
 
+    @cached_method
     def characteristic_polynomial(self):
         """
         EXAMPLES:
@@ -104,9 +104,6 @@ class FiniteDimensionalEuclideanJordanAlgebra(FiniteDimensionalAlgebra):
             t^2 - 2*t + 1
 
         """
-        if self._charpoly is not None:
-            return self._charpoly
-
         r = self.rank()
         n = self.dimension()
 
@@ -162,8 +159,7 @@ class FiniteDimensionalEuclideanJordanAlgebra(FiniteDimensionalAlgebra):
             # assign a[r] goes out-of-bounds.
             a.append(1) # corresponds to x^r
 
-        self._charpoly = sum( a[k]*(t**k) for k in range(len(a)) )
-        return self._charpoly
+        return sum( a[k]*(t**k) for k in range(len(a)) )
 
 
     def inner_product(self, x, y):