From: Michael Orlitzky <michael@orlitzky.com>
Date: Sat, 7 Nov 2020 19:45:54 +0000 (-0500)
Subject: eja: add "of" to the algebra characteristic_polynomial() method name.
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=d3e40bda3f50a2101103192b91b2ab2a911c0311;p=sage.d.git

eja: add "of" to the algebra characteristic_polynomial() method name.
---

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 8d212e1..e02257f 100644
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -10,6 +10,3 @@
 
 5. Factor out the unit-norm basis (and operator symmetry) tests once
    all of the algebras pass.
-
-6. Rename the algebra "characteristic polynomial" method to
-   "characteristic polynomial of."
diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 4e66b2d..9aa40ee 100644
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -236,10 +236,12 @@ class FiniteDimensionalEuclideanJordanAlgebra(CombinatorialFreeModule):
         return self._multiplication_table[i][j]
 
     @cached_method
-    def characteristic_polynomial(self):
+    def characteristic_polynomial_of(self):
         """
-        Return a characteristic polynomial that works for all elements
-        of this algebra.
+        Return the algebra's "characteristic polynomial of" function,
+        which is itself a multivariate polynomial that, when evaluated
+        at the coordinates of some algebra element, returns that
+        element's characteristic polynomial.
 
         The resulting polynomial has `n+1` variables, where `n` is the
         dimension of this algebra. The first `n` variables correspond to
@@ -259,7 +261,7 @@ class FiniteDimensionalEuclideanJordanAlgebra(CombinatorialFreeModule):
         Alizadeh, Example 11.11::
 
             sage: J = JordanSpinEJA(3)
-            sage: p = J.characteristic_polynomial(); p
+            sage: p = J.characteristic_polynomial_of(); p
             X1^2 - X2^2 - X3^2 + (-2*t)*X1 + t^2
             sage: xvec = J.one().to_vector()
             sage: p(*xvec)
@@ -272,7 +274,7 @@ class FiniteDimensionalEuclideanJordanAlgebra(CombinatorialFreeModule):
         any argument::
 
             sage: J = TrivialEJA()
-            sage: J.characteristic_polynomial()
+            sage: J.characteristic_polynomial_of()
             1
 
         """
diff --git a/mjo/eja/eja_element.py b/mjo/eja/eja_element.py
index a6230a4..0be0032 100644
--- a/mjo/eja/eja_element.py
+++ b/mjo/eja/eja_element.py
@@ -181,7 +181,7 @@ class FiniteDimensionalEuclideanJordanAlgebraElement(IndexedFreeModuleElement):
             True
 
         """
-        p = self.parent().characteristic_polynomial()
+        p = self.parent().characteristic_polynomial_of()
         return p(*self.to_vector())