From 7e1d491752f8cf3c56d9bc03a89d048d0f3a88b9 Mon Sep 17 00:00:00 2001
From: Patrick Ersing <114223904+patrickersing@users.noreply.github.com>
Date: Wed, 21 Aug 2024 11:33:32 +0200
Subject: [PATCH] apply absolute value function (#55)

---
 src/equations/shallow_water_exner_1d.jl | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/equations/shallow_water_exner_1d.jl b/src/equations/shallow_water_exner_1d.jl
index 3aa34c9..cf77759 100644
--- a/src/equations/shallow_water_exner_1d.jl
+++ b/src/equations/shallow_water_exner_1d.jl
@@ -469,11 +469,12 @@ end
 
 @inline function Trixi.max_abs_speed_naive(u_ll, u_rr, orientation::Integer,
                                            equations::ShallowWaterExnerEquations1D)
-    return max(eigvals_cardano(u_rr, equations)..., eigvals_cardano(u_ll, equations)...)
+    return max(maximum(abs, eigvals_cardano(u_rr, equations)),
+               maximum(abs, eigvals_cardano(u_ll, equations)))
 end
 
 @inline function Trixi.max_abs_speeds(u, equations::ShallowWaterExnerEquations1D)
-    return maximum(eigvals_cardano(u, equations))
+    return maximum(abs, eigvals_cardano(u, equations))
 end
 
 #Helper function to extract the velocity vector from the conservative variables