From 6336fe9db608f7610622cc4520a2d45b55622e51 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sat, 24 Nov 2018 01:31:15 +0100
Subject: [PATCH] rogueviz::kohonen:: halt with error when reading graph
 unsuccessfully

---
 rogueviz-kohonen.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/rogueviz-kohonen.cpp b/rogueviz-kohonen.cpp
index f99e063c..980c2092 100644
--- a/rogueviz-kohonen.cpp
+++ b/rogueviz-kohonen.cpp
@@ -1100,7 +1100,12 @@ void load_edges(const string& fname_edges, string edgename, int pick = 0) {
   distribute_neurons();
   int i = 0;
   for(auto p: edgedata2)
-    addedge(p.first, p.second, 1 / (i+++.5), true, t);
+    if(p.first >= 0 && p.second >= 0)
+      addedge(p.first, p.second, 1 / (i+++.5), true, t);
+    else {
+      printf("error reading graph\n");
+      exit(1);
+      }
   }
 
 void random_edges(int q) {