From 087e4f0cfffc6d33cddaad0c62fa3ca026ff5f28 Mon Sep 17 00:00:00 2001 From: Michael Orlitzky Date: Tue, 3 Mar 2026 22:26:47 -0500 Subject: [PATCH] mjo/clan/jordan_spin_clan.py: add a comment about the inner product --- mjo/clan/jordan_spin_clan.py | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mjo/clan/jordan_spin_clan.py b/mjo/clan/jordan_spin_clan.py index 5d836d0..7eabc84 100644 --- a/mjo/clan/jordan_spin_clan.py +++ b/mjo/clan/jordan_spin_clan.py @@ -102,8 +102,15 @@ class JordanSpinClan(NormalDecomposition): return RN.from_vector(V(z_coords)) def ip(x,y): + # The Ishi inner product. That this is NOT the Euclidean + # inner product on coordinates, because (from cp(x,y) + # above) this one is, + # + # x11*y11 + x22*y22 + 2 + # + # (The off-diagonals are weighted more than usual.) p = cp(x,y) / two - return p[(0,0,1)] + p[(1,1,1)] # sum of diagonals + return p[(0,0,1)] + p[(1,1,1)] super().__init__(RN, cp, ip, **kwargs) -- 2.51.0