From aef77d17290066169a24d9b4d29584ce4d0f9c18 Mon Sep 17 00:00:00 2001
From: michellethomas <michelle.q.thomas@gmail.com>
Date: Mon, 16 Oct 2017 16:31:07 -0700
Subject: [PATCH] Avoid dividing by zero for sparkline in time table viz
 (#3679)

---
 superset/assets/visualizations/time_table.jsx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/superset/assets/visualizations/time_table.jsx b/superset/assets/visualizations/time_table.jsx
index 4a6e179ca4c2a..9b687f13ae12a 100644
--- a/superset/assets/visualizations/time_table.jsx
+++ b/superset/assets/visualizations/time_table.jsx
@@ -72,7 +72,12 @@ function viz(slice, payload) {
           // Period ratio sparkline
           sparkData = [];
           for (let i = c.timeRatio; i < data.length; i++) {
-            sparkData.push(data[i][metric] / data[i - c.timeRatio][metric]);
+            const prevData = data[i - c.timeRatio][metric];
+            if (prevData && prevData !== 0) {
+              sparkData.push(data[i][metric] / prevData);
+            } else {
+              sparkData.push(null);
+            }
           }
         }
         const extent = d3.extent(sparkData);