diff --git a/HistoryMatching/HistoryMatching.R b/HistoryMatching/HistoryMatching.R
index f132d68..60dc338 100644
--- a/HistoryMatching/HistoryMatching.R
+++ b/HistoryMatching/HistoryMatching.R
@@ -151,11 +151,13 @@ ImpDensityPanelWaveM <- function(x1var, x2var, ImpData, nEms, Resolution=c(10,10
 CreateImpList <- function(whichVars, VarNames, ImpData, nEms=1, Resolution=c(15,15), whichMax=3,Cutoff=3){
   combGrid <- expand.grid(whichVars[-length(whichVars)],whichVars[-1])
   badRows <- c()
-  for(i in 1:length(combGrid[,1])){
-    if(combGrid[i,1] >= combGrid[i,2])
-      badRows <- c(badRows,i)
-  }
-  combGrid <- combGrid[-badRows,]
+  if (length(combGrid[,1])>1) {
+    for(i in 1:length(combGrid[,1])){
+      if(combGrid[i,1] >= combGrid[i,2])
+        badRows <- c(badRows,i)
+    }
+    combGrid <- combGrid[-badRows,]
+  } 
   combGrid <- combGrid[do.call(order,combGrid),]
   gridList <- lapply(whichVars[-length(whichVars)], function(k) combGrid[which(combGrid[,1]==k),])
   lapply(gridList, function(e) lapply(1:length(e[,1]), function(k) 
@@ -168,11 +170,13 @@ CreateImpListWaveM <- function(whichVars, VarNames, ImpData, nEms=1, Resolution=
                                whichMax= 3){
   combGrid <- expand.grid(whichVars[-length(whichVars)],whichVars[-1])
   badRows <- c()
-  for(i in 1:length(combGrid[,1])){
-    if(combGrid[i,1] >= combGrid[i,2])
-      badRows <- c(badRows,i)
-  }
-  combGrid <- combGrid[-badRows,]
+  if (length(combGrid[,1])>1) {
+    for(i in 1:length(combGrid[,1])){
+      if(combGrid[i,1] >= combGrid[i,2])
+        badRows <- c(badRows,i)
+    }
+    combGrid <- combGrid[-badRows,]
+  } 
   combGrid <- combGrid[do.call(order,combGrid),]
   gridList <- lapply(whichVars[-length(whichVars)], function(k) combGrid[which(combGrid[,1]==k),])
   lapply(gridList, function(e) lapply(1:length(e[,1]), function(k)