diff --git a/rowers/datautils.py b/rowers/datautils.py
index 1358e0d6..34c13421 100644
--- a/rowers/datautils.py
+++ b/rowers/datautils.py
@@ -252,7 +252,7 @@ def getcp(dfgrouped,logarr):
             
             dt = pd.Series(dt)
             cpw = pd.Series(cpw)
-            if len(dt):
+            if len(dt)>2:
                 cpvalues = griddata(dt.values,
                                     cpw.values,
                                     logarr,method='linear',