[SPARK-7710] add doc examples for DataFrameStatFunctions

[brkyvz]

Example code was added to API doc. Didn't test it yet.

@rxin

[SparkQA]

Test build #33837 has finished for PR 6531 at commit 9714fde.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #33967 has finished for PR 6531 at commit d5d0ea8.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[marmbrus]

You have some UTF-8 sneaking in here which causes it to render weirdly:

[brkyvz]

had to change this to sc.parallelize(...).toDF(...) because sqlContext.createDataFrame(0 until 10) doesn't work because it needs to be a tuple I guess.

[brkyvz]

@marmbrus this is ready to merge. Verified the examples in Spark Shell.

[SparkQA]

Test build #35614 has finished for PR 6531 at commit e4df3b7.

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

[SparkQA]

Test build #35618 has finished for PR 6531 at commit 4219e66.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[brkyvz]

retest this please

[SparkQA]

Test build #35702 has finished for PR 6531 at commit 4219e66.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[marmbrus]

What about including the (truncated) output of show()?

[brkyvz]

Closed in favor of #8378.