diff --git a/frontend/frontend.js b/frontend/frontend.js
index 281f142..1c14afa 100644
--- a/frontend/frontend.js
+++ b/frontend/frontend.js
@@ -29,7 +29,7 @@ function fillTable (obj, dom) {
 function graphSpectralData (obj, dom) {
   // graphs the data from obj[0] into canvas at dom
   var arr = [];
-  ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'R', 'I', 'S', 'J', 'T', 'U', 'V', 'W', 'K', 'L'].forEach(function () {
+  ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'R', 'I', 'S', 'J', 'T', 'U', 'V', 'W', 'K', 'L'].forEach(function (i) {
     arr.push(obj[i]);
   });
   var chart = new Chart(dom, {