From 61f9c8711c79f35d67b0456155866da316b131d9 Mon Sep 17 00:00:00 2001 From: Yuhao Yang Date: Mon, 9 Nov 2015 16:55:23 -0800 Subject: [SPARK-11069][ML] Add RegexTokenizer option to convert to lowercase jira: https://issues.apache.org/jira/browse/SPARK-11069 quotes from jira: Tokenizer converts strings to lowercase automatically, but RegexTokenizer does not. It would be nice to add an option to RegexTokenizer to convert to lowercase. Proposal: call the Boolean Param "toLowercase" set default to false (so behavior does not change) Actually sklearn converts to lowercase before tokenizing too Author: Yuhao Yang Closes #9092 from hhbyyh/tokenLower. --- .../scala/org/apache/spark/ml/feature/Tokenizer.scala | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'mllib/src/main/scala/org') diff --git a/mllib/src/main/scala/org/apache/spark/ml/feature/Tokenizer.scala b/mllib/src/main/scala/org/apache/spark/ml/feature/Tokenizer.scala index 248288ca73..1b82b40caa 100644 --- a/mllib/src/main/scala/org/apache/spark/ml/feature/Tokenizer.scala +++ b/mllib/src/main/scala/org/apache/spark/ml/feature/Tokenizer.scala @@ -100,10 +100,25 @@ class RegexTokenizer(override val uid: String) /** @group getParam */ def getPattern: String = $(pattern) - setDefault(minTokenLength -> 1, gaps -> true, pattern -> "\\s+") + /** + * Indicates whether to convert all characters to lowercase before tokenizing. + * Default: true + * @group param + */ + final val toLowercase: BooleanParam = new BooleanParam(this, "toLowercase", + "whether to convert all characters to lowercase before tokenizing.") + + /** @group setParam */ + def setToLowercase(value: Boolean): this.type = set(toLowercase, value) + + /** @group getParam */ + def getToLowercase: Boolean = $(toLowercase) + + setDefault(minTokenLength -> 1, gaps -> true, pattern -> "\\s+", toLowercase -> true) - override protected def createTransformFunc: String => Seq[String] = { str => + override protected def createTransformFunc: String => Seq[String] = { originStr => val re = $(pattern).r + val str = if ($(toLowercase)) originStr.toLowerCase() else originStr val tokens = if ($(gaps)) re.split(str).toSeq else re.findAllIn(str).toSeq val minLength = $(minTokenLength) tokens.filter(_.length >= minLength) -- cgit v1.2.3