diff --git a/tools/filters/compare.xml b/tools/filters/compare.xml
index 395b622f097..2eca79af15a 100644
--- a/tools/filters/compare.xml
+++ b/tools/filters/compare.xml
@@ -3,9 +3,13 @@
   <command interpreter="python">joinWrapper.py $input1 $input2 $field1 $field2 $mode $out_file1</command>
   <inputs>
     <param format="tabular" name="input1" type="data" label="Compare"/>
-    <param name="field1" label="Using column" type="data_column" data_ref="input1" />
+    <param name="field1" label="Using column" type="data_column" data_ref="input1">
+        <validator type="no_options" message="Invalid column choice. Please try again after editing metadata of your input dataset by clicking on the pencil icon next to it."/>
+    </param>
     <param format="tabular" name="input2" type="data" label="against" />
-    <param name="field2" label="and column" type="data_column" data_ref="input2" />
+    <param name="field2" label="and column" type="data_column" data_ref="input2">
+            <validator type="no_options" message="Invalid column choice. Please try again after editing metadata of your input dataset by clicking on the pencil icon next to it."/>
+    </param>
     <param name="mode" type="select" label="To find" help="See examples below for explanation of these options">
       <option value="N">Matching rows of 1st query</option>
       <option value="V">Non Matching rows of 1st query</option>
diff --git a/tools/stats/filtering.py b/tools/stats/filtering.py
index 6826a9bed83..502f22d2381 100644
--- a/tools/stats/filtering.py
+++ b/tools/stats/filtering.py
@@ -25,6 +25,7 @@ out_fname = sys.argv[2]
 cond_text = sys.argv[3]
 try:
     in_columns = int( sys.argv[4] )
+    assert sys.argv[5]  #check to see that the column types varaible isn't null
     in_column_types = sys.argv[5].split( ',' )
 except:
     stop_err( "Data does not appear to be tabular.  This tool can only be used with tab-delimited data." )
diff --git a/tools/stats/grouping.py b/tools/stats/grouping.py
index a26fb033f0b..5ebb2cc79c4 100644
--- a/tools/stats/grouping.py
+++ b/tools/stats/grouping.py
@@ -128,7 +128,7 @@ def main():
                             if op not in ['c','length','unique','random']:
                                 for j, elem in enumerate( prev_vals[i] ):
                                     prev_vals[i][j] = float( elem )
-                                rout = "%f" %( eval( rfunc )( prev_vals[i] ))
+                                rout = "%g" %( eval( rfunc )( prev_vals[i] ))
                                 if rounds[i] == 'yes':
                                     rout = int(round(float(rout)))
                             else:
@@ -179,7 +179,7 @@ def main():
             if op not in ['c','length','unique','random']:
                 for j, elem in enumerate( prev_vals[i] ):
                     prev_vals[i][j] = float( elem )
-                rout = '%f' %( eval( rfunc )( prev_vals[i] ))
+                rout = '%g' %( eval( rfunc )( prev_vals[i] ))
                 if rounds[i] == 'yes':
                     rout = int(round(float(rout)))
             else: