diff --git a/.gitignore b/.gitignore
index ef8ff1bdb09a2080278ae1f9d96ac90bd3f1dc07..bbf1a37ad12edf6e34649119e688f33e39a5b13c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
 *.mex*
-IQM Tools/IQMpro/tools/01-MEXmodels/CVODEMEX/lib/CVODEmex25.lib
\ No newline at end of file
+
diff --git a/nonunique.m b/nonunique.m
new file mode 100644
index 0000000000000000000000000000000000000000..cda8d85885cc94a9b66cb3e12e2be95a6fb858b4
--- /dev/null
+++ b/nonunique.m
@@ -0,0 +1,6 @@
+function [dupes, ind] = nonunique(A)
+[~, i, ~] = unique(A,'first');
+dupes = A(not(ismember(1:numel(A),i)));
+ind=ismember(A,dupes);
+end
+