From ec3e687b0c07ccb7a36f4136a2341dd0c88d82c9 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Mon, 10 Feb 2020 16:22:23 -0500
Subject: [PATCH] fix bug in set type/ratio when operating on subsets

---
 src/set.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/set.cpp b/src/set.cpp
index 9807b07ea4..d61ffae6ae 100644
--- a/src/set.cpp
+++ b/src/set.cpp
@@ -1084,13 +1084,18 @@ void Set::setrandom(int keyword)
     ranmars->select_subset(nsubset,count,flag,work);
 
     // change types of selected atoms
+    // flag vecftor from select_subset() is only for eligible atoms
 
     count = 0;
-    for (i = 0; i < nlocal; i++)
-      if (select[i] && flag[i]) {
+    int eligible = 0;
+    for (i = 0; i < nlocal; i++) {
+      if (!select[i]) continue;
+      if (flag[eligible]) {
         atom->type[i] = newtype;
         count++;
       }
+      eligible++;
+    }
 
     // clean up