diff options
Diffstat (limited to 'sql')
-rw-r--r-- | sql/core/src/main/scala/org/apache/spark/sql/DataFrameStatFunctions.scala | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameStatFunctions.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameStatFunctions.scala index 23652aeb7c..e8fa829477 100644 --- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrameStatFunctions.scala +++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrameStatFunctions.scala @@ -43,7 +43,10 @@ final class DataFrameStatFunctions private[sql](df: DataFrame) { } /** - * Runs `freqItems` with a default `support` of 1%. + * Finding frequent items for columns, possibly with false positives. Using the + * frequent element count algorithm described in + * [[http://dx.doi.org/10.1145/762471.762473, proposed by Karp, Schenker, and Papadimitriou]]. + * Uses a `default` support of 1%. * * @param cols the names of the columns to search frequent items in. * @return A Local DataFrame with the Array of frequent items for each column. @@ -55,14 +58,14 @@ final class DataFrameStatFunctions private[sql](df: DataFrame) { /** * Python friendly implementation for `freqItems` */ - def freqItems(cols: List[String], support: Double): DataFrame = { + def freqItems(cols: Seq[String], support: Double): DataFrame = { FrequentItems.singlePassFreqItems(df, cols, support) } /** * Python friendly implementation for `freqItems` with a default `support` of 1%. */ - def freqItems(cols: List[String]): DataFrame = { + def freqItems(cols: Seq[String]): DataFrame = { FrequentItems.singlePassFreqItems(df, cols, 0.01) } |