eja: fix the rank of the spin factor algebra.

diff --git a/mjo/eja/euclidean_jordan_algebra.py b/mjo/eja/euclidean_jordan_algebra.py
index 849243c81d56a2781a8b0abe5c9e6ae795f264eb..1f037688eee6f0f2931ef5ba311de0a96da6cea0 100644 (file)
--- a/mjo/eja/euclidean_jordan_algebra.py
+++ b/mjo/eja/euclidean_jordan_algebra.py
@@ -317,4 +317,8 @@ def eja_ln(dimension, field=QQ):
         Qi[0,0] = Qi[0,0] * ~field(2)
         Qs.append(Qi)
 
-    return FiniteDimensionalEuclideanJordanAlgebra(field,Qs,rank=2)
+    # The rank of the spin factor algebra is two, UNLESS we're in a
+    # one-dimensional ambient space (the rank is bounded by the
+    # ambient dimension).
+    rank = min(dimension,2)
+    return FiniteDimensionalEuclideanJordanAlgebra(field,Qs,rank=rank)