From f66816060b19cb7816d41b33184e90a7c51d1f0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Ingvar=20Dahlgren?= <bjodah@gmail.com>
Date: Sun, 15 Sep 2024 14:36:18 +0200
Subject: [PATCH] update heaviside argument

---
 chempy/kinetics/rates.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/chempy/kinetics/rates.py b/chempy/kinetics/rates.py
index 54556bb4..9bc0e08d 100644
--- a/chempy/kinetics/rates.py
+++ b/chempy/kinetics/rates.py
@@ -198,8 +198,9 @@ def heaviside(x, z):
         elif hasattr(backend, 'clip'):  # e.g. numpy
             def heaviside(x, z):
                 assert z == 0
-                lx = backend.log(backend.maximum(x, tiny))
-                xclp = be.clip(lx, lo, hi)
+                lx = backend.log(backend.maximum(backend.array(x), tiny))
+                xclp = backend.clip(lx, lo, hi)
+                x = (xclp - lo)/(hi - lo)
                 y = (3 - 2*x)*x*x
                 return y
         else: