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apache · Jun 10, 2015 · 4cb764d · 4cb764d
1 parent 0f78682
commit 4cb764d
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Showing 4 changed files with 12 additions and 5 deletions.
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala
@@ -39,6 +39,9 @@ abstract class AbstractUnaryMathExpression[T, U](name: String)
   def funcName: String = name.toLowerCase
 }
 
+/**
+ * Base for [[AbstractUnaryMathExpression]] that accepts a Double and returns a Double.
+ */
 abstract class UnaryMathExpression(f: Double => Double, name: String)
   extends AbstractUnaryMathExpression[Double, Double](name) {
   self: Product =>

diff --git a/...atalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/MathFunctionsSuite.scala b/...atalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/MathFunctionsSuite.scala
@@ -26,10 +26,11 @@ class MathFunctionsSuite extends SparkFunSuite with ExpressionEvalHelper {
    * Used for testing unary math expressions.
    *
    * @param c expression
-   * @param f The functions in scala.math
+   * @param f The functions in scala.math or elsewhere used to generate expected results
    * @param domain The set of values to run the function with
    * @param expectNull Whether the given values should return null or not
    * @tparam T Generic type for primitives
+   * @tparam U Generic type for the output of the given function `f`
    */
   private def testUnary[T, U](
       c: Expression => Expression,

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
@@ -1300,15 +1300,17 @@ object functions {
   def toRadians(columnName: String): Column = toRadians(Column(columnName))
 
   /**
-   * Computes the binary format of the given value.
+   * An expression that returns the string representation of the binary value of the given long
+   * column. For example, bin("12") returns "1100".
    *
    * @group math_funcs
    * @since 1.4.0
    */
   def bin(e: Column): Column = Bin(e.expr)
 
   /**
-   * Computes the binary format of the given value.
+   * An expression that returns the string representation of the binary value of the given long
+   * column. For example, bin("12") returns "1100".
    *
    * @group math_funcs
    * @since 1.4.0

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameFunctionsSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameFunctionsSuite.scala
@@ -94,8 +94,9 @@ class DataFrameFunctionsSuite extends QueryTest {
   }
 
   test("bin") {
+    val df = Seq[(Integer, Integer)]((12, null)).toDF("a", "b")
     checkAnswer(
-      testData2.select(bin($"a")),
-      testData2.collect().toSeq.map(r => Row(JLong.toBinaryString(r.getInt(0).toLong))))
+      df.select(bin("a"), bin("b")),
+      Row("1100", null))
   }
 }