eja: fix the matrix EJA trace inner-product.

diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py
index 18138f4c2a8ca4fad76b79de29d0e64e09a6435f..1cf6fa51dd2626df1e75dcaeab95fc743000130f 100644 (file)
--- a/mjo/eja/eja_algebra.py
+++ b/mjo/eja/eja_algebra.py
@@ -1737,7 +1737,7 @@ class MatrixEJA:
         """
         # We take the norm (absolute value) because Octonions() isn't
         # smart enough yet to coerce its one() into the base field.
-        return (X*Y).trace().abs()
+        return (X*Y).trace().real().abs()
 
 class RealEmbeddedMatrixEJA(MatrixEJA):
     @staticmethod