[SPARK-8265] [MLlib] [PySpark] Add LinearDataGenerator to pyspark.mllib.utils

[MechCoder]

It is useful to generate linear data for easy testing of linear models and in general. Scala already has it. This is just a wrapper around the Scala code.

[MechCoder]

cc: @davies Please have a look.

[SparkQA]

Test build #34492 has finished for PR 6715 at commit f234b4c.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class LinearDataGenerator(object):

[MechCoder]

ping @mengxr I fixed the minor style fixes and pushed. Hopefully it should look good now.

[SparkQA]

Test build #35148 has finished for PR 6715 at commit b10ced1.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class LinearDataGenerator(object):

[SparkQA]

Test build #35147 has finished for PR 6715 at commit 504ae9a.

• This patch passes all tests.
• This patch does not merge cleanly.
• This patch adds the following public classes (experimental):
  • class LinearDataGenerator(object):

[MechCoder]

jenkins retest this please

[mengxr]

use named arguments to make the code more readable

[SparkQA]

Test build #35162 has finished for PR 6715 at commit b10ced1.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class LinearDataGenerator(object):

[MechCoder]

@mengxr Thanks for your comments. I have addressed them.

[SparkQA]

Test build #35221 has finished for PR 6715 at commit 1bce3f5.

• This patch fails Python style tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class LinearDataGenerator(object):

[SparkQA]

Test build #35224 has finished for PR 6715 at commit 3e5b51d.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class LinearDataGenerator(object):

[MechCoder]

Rebased over master.

[SparkQA]

Test build #35312 has finished for PR 6715 at commit 6182884.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • // class ParentClass(parentField: Int)
  • // class ChildClass(childField: Int) extends ParentClass(1)
  • // If the class type corresponding to current slot has writeObject() defined,
  • // then its not obvious which fields of the class will be serialized as the writeObject()
  • class StreamingKMeansModel(KMeansModel):
  • class StreamingKMeans(object):
  • class LinearDataGenerator(object):
  • abstract class GeneratedClass
  • case class Md5(child: Expression)

[mengxr]

LGTM. Merged into master. Thanks! Apache JIRA is down. I will update the JIRA later.