diff --git a/src/FTCS.cpp b/src/FTCS.cpp
index 2bb5028..4dc8c64 100644
--- a/src/FTCS.cpp
+++ b/src/FTCS.cpp
@@ -30,6 +30,11 @@ double calcHorizontalChange(Grid grid, int row, int col) {
 }
 
 
+double calcHorizontalChangeClosed() {
+    return 0;
+}
+
+
 double calcVerticalChange(Grid grid, int row, int col) {
     
     double result =