From 6b017df71b7ad107cdcb6d6ef85c8b4c539d8c8e Mon Sep 17 00:00:00 2001
From: Douwe Schulte <d.schulte@uu.nl>
Date: Tue, 7 Nov 2023 15:42:21 +0100
Subject: [PATCH] Fixed ppm calculation for negative numbers

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

diff --git a/src/system.rs b/src/system.rs
index e3a7674..2b9d7a3 100644
--- a/src/system.rs
+++ b/src/system.rs
@@ -142,6 +142,6 @@ impl MassOverCharge {
 impl Mass {
     /// Absolute ppm error between this number and the given other
     pub fn ppm(self, b: Self) -> f64 {
-        ((self - b).abs() / self).value * 1e6
+        ((self - b).abs() / self.abs()).value * 1e6
     }
 }