From db8722faf8f7c7b0de0f3bd8a02c19bf9592e429 Mon Sep 17 00:00:00 2001
From: Gregory Eslinger <gregjesl@gmail.com>
Date: Sun, 13 Oct 2024 23:01:13 -0400
Subject: [PATCH] Fixed sign error

---
 src/dynamics/sph_harmonics.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/dynamics/sph_harmonics.rs b/src/dynamics/sph_harmonics.rs
index 073d47fe..f070902b 100644
--- a/src/dynamics/sph_harmonics.rs
+++ b/src/dynamics/sph_harmonics.rs
@@ -231,7 +231,7 @@ impl AccelModel for Harmonics {
                 sum.x += (m as f64) * a_nm[(n, m)] * e_;
                 sum.y += (m as f64) * a_nm[(n, m)] * f_;
                 sum.z += self.vr01[(n, m)] * a_nm[(n, m + 1)] * d_;
-                sum.w += self.vr11[(n, m)] * a_nm[(n + 1, m + 1)] * d_;
+                sum.w -= self.vr11[(n, m)] * a_nm[(n + 1, m + 1)] * d_;
             }
             let rr = rho_np1 / eq_radius_km;
             accel4 += rr * sum;