From e66eccf16ff5c3ae58d72fb3f4ab6518433b6afe Mon Sep 17 00:00:00 2001
From: James Krieger <jamesmkrieger@gmail.com>
Date: Sun, 28 Jul 2024 18:11:26 +0200
Subject: [PATCH] add first to goto

---
 prody/apps/prody_apps/prody_catdcd.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/prody/apps/prody_apps/prody_catdcd.py b/prody/apps/prody_apps/prody_catdcd.py
index 8ce4e378c..a71c2bbdb 100644
--- a/prody/apps/prody_apps/prody_catdcd.py
+++ b/prody/apps/prody_apps/prody_catdcd.py
@@ -80,8 +80,9 @@ def prody_catdcd(*dcd, **kwargs):
     out = prody.DCDFile(output, 'w')
     count = 0
     stride = kwargs.get('stride', 1)
-    goto = stride != 1
-    slc = slice(kwargs.get('first', 0), kwargs.get('last', -1),
+    first = kwargs.get('first', 0)
+    goto = stride != 1 or first != 0
+    slc = slice(first, kwargs.get('last', -1),
                 stride).indices(len(traj)+1)
     for i in range(*slc):
         if goto: