From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 25 Jun 2019 21:13:41 +0000 (-0400)
Subject: eja: recurse more directly in minimal_polynomial().
X-Git-Url: http://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=0dc6a110a16f63240e7817fc7529996e885973c8;hp=556690d808d614f2c271dc431dd909e353530594;p=sage.d.git

eja: recurse more directly in minimal_polynomial().
---

diff --git a/mjo/eja/euclidean_jordan_algebra.py b/mjo/eja/euclidean_jordan_algebra.py
index bb46019..8f623b4 100644
--- a/mjo/eja/euclidean_jordan_algebra.py
+++ b/mjo/eja/euclidean_jordan_algebra.py
@@ -242,18 +242,25 @@ class FiniteDimensionalEuclideanJordanAlgebra(FiniteDimensionalAlgebra):
                 True
 
             """
-            if self.parent().is_associative():
-                return self.matrix().minimal_polynomial()
+            # The element we're going to call "minimal_polynomial()" on.
+            # Either myself, interpreted as an element of a finite-
+            # dimensional algebra, or an element of an associative
+            # subalgebra.
+            elt = None
 
-            V = self.span_of_powers()
-            assoc_subalg = self.subalgebra_generated_by()
-            # Mis-design warning: the basis used for span_of_powers()
-            # and subalgebra_generated_by() must be the same, and in
-            # the same order!
-            subalg_self = assoc_subalg(V.coordinates(self.vector()))
-            # Recursive call, but should work since the subalgebra is
-            # associative.
-            return subalg_self.minimal_polynomial()
+            if self.parent().is_associative():
+                elt = FiniteDimensionalAlgebraElement(self.parent(), self)
+            else:
+                V = self.span_of_powers()
+                assoc_subalg = self.subalgebra_generated_by()
+                # Mis-design warning: the basis used for span_of_powers()
+                # and subalgebra_generated_by() must be the same, and in
+                # the same order!
+                elt = assoc_subalg(V.coordinates(self.vector()))
+
+            # Recursive call, but should work since elt lives in an
+            # associative algebra.
+            return elt.minimal_polynomial()
 
 
         def characteristic_polynomial(self):