diff --git a/src/main/java/com/highperformancespark/examples/dataframe/JavaHappyPandas.java b/src/main/java/com/highperformancespark/examples/dataframe/JavaHappyPandas.java
index 09b5e2f..bc93163 100644
--- a/src/main/java/com/highperformancespark/examples/dataframe/JavaHappyPandas.java
+++ b/src/main/java/com/highperformancespark/examples/dataframe/JavaHappyPandas.java
@@ -62,7 +62,7 @@ public static DataFrame jsonLoadFromRDD(SQLContext sqlContext, JavaRDD<String> i
    */
   public static DataFrame happyPandasPercentage(DataFrame pandaInfo) {
     DataFrame happyPercentage = pandaInfo.select(pandaInfo.col("place"),
-      pandaInfo.col("happyPandas").divide(pandaInfo.col("totalPandas")).as("percentHappy"));
+      (pandaInfo.col("happyPandas").divide(pandaInfo.col("totalPandas"))).as("percentHappy"));
     return happyPercentage;
   }
 
@@ -204,7 +204,7 @@ public static void joins(DataFrame df1, DataFrame df2) {
   }
 
   public static DataFrame selfJoin(DataFrame df) {
-    return df.as("a").join(df.as("b")).where(df.col("name").equalTo(df.col("name")));
+    return (df.as("a")).join(df.as("b")).where("a.name = b.name");
   }
 
 }
diff --git a/src/test/scala/com/high-performance-spark-examples/dataframe/HappyPandasTest.scala b/src/test/scala/com/high-performance-spark-examples/dataframe/HappyPandasTest.scala
index f46a2f3..c6d64fe 100644
--- a/src/test/scala/com/high-performance-spark-examples/dataframe/HappyPandasTest.scala
+++ b/src/test/scala/com/high-performance-spark-examples/dataframe/HappyPandasTest.scala
@@ -54,14 +54,14 @@ class HappyPandasTest extends DataFrameSuiteBase {
   //tag::approxEqualDataFrames[]
 
   test("verify simple happy pandas Percentage") {
-    val expectedResult = List(Row(toronto, 0.5), Row(sandiego, 2/3.0), Row(virginia, 1/10.0))
-    val expectedDf = createDF(expectedResult, ("place", StringType),
+    val expectedList = List(Row(toronto, 0.5), Row(sandiego, 2/3.0), Row(virginia, 1/10.0))
+    val expectedDf = createDF(expectedList, ("place", StringType),
                                               ("percentHappy", DoubleType))
 
     val inputDF = sqlContext.createDataFrame(pandaInfoList)
-    val result = HappyPandas.happyPandasPercentage(inputDF)
+    val resultDF = HappyPandas.happyPandasPercentage(inputDF)
 
-    assertDataFrameApproximateEquals(expectedDf, result, 1E-5)
+    assertDataFrameApproximateEquals(expectedDf, resultDF, 1E-5)
   }
   //end::approxEqualDataFrames[]