This PR is based on #7208 , thanks to HuJiayin

Closes #7208

Author: HuJiayin <jiayin.hu@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7850 from davies/initcap and squashes the following commits:

54472e9 [Davies Liu] fix python test
17ffe51 [Davies Liu] Merge branch 'master' of github.com:apache/spark into initcap
ca46390 [Davies Liu] Merge branch 'master' of github.com:apache/spark into initcap
3a906e4 [Davies Liu] implement title case in UTF8String
8b2506a [HuJiayin] Update functions.py
2cd43e5 [HuJiayin] fix python style check
b616c0e [HuJiayin] add python api
1f5a0ef [HuJiayin] add codegen
7e0c604 [HuJiayin] Merge branch 'master' of https://github.com/apache/spark into initcap
6a0b958 [HuJiayin] add column
c79482d [HuJiayin] support soundex
7ce416b [HuJiayin] support initcap rebase code

This is based on #7641, thanks to zhichao-li

Closes #7641

Author: zhichao.li <zhichao.li@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7848 from davies/substr and squashes the following commits:

461b709 [Davies Liu] remove bytearry from tests
b45377a [Davies Liu] Merge branch 'master' of github.com:apache/spark into substr
01d795e [zhichao.li] scala style
99aa130 [zhichao.li] add substring to dataframe
4f68bfe [zhichao.li] add binary type support for substring

This PR is based on #7581 , just fix the conflict.

Author: Cheng Hao <hao.cheng@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7851 from davies/sort_array and squashes the following commits:

a80ef66 [Davies Liu] fix conflict
7cfda65 [Davies Liu] Merge branch 'master' of github.com:apache/spark into sort_array
664c960 [Cheng Hao] update the sort_array by using the ArrayData
276d2d5 [Cheng Hao] add empty line
0edab9c [Cheng Hao] Add asending/descending support for sort_array
80fc0f8 [Cheng Hao] Add type checking
a42b678 [Cheng Hao] Add sort_array support

This reverts commit 67ad4e21.

Add expression `sort_array` support.

Author: Cheng Hao <hao.cheng@intel.com>

This patch had conflicts when merged, resolved by
Committer: Davies Liu <davies.liu@gmail.com>

Closes #7581 from chenghao-intel/sort_array and squashes the following commits:

664c960 [Cheng Hao] update the sort_array by using the ArrayData
276d2d5 [Cheng Hao] add empty line
0edab9c [Cheng Hao] Add asending/descending support for sort_array
80fc0f8 [Cheng Hao] Add type checking
a42b678 [Cheng Hao] Add sort_array support

This PR is based on #7533 , thanks to zhichao-li

Closes #7533

Author: zhichao.li <zhichao.li@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7843 from davies/str_index and squashes the following commits:

391347b [Davies Liu] add python api
3ce7802 [Davies Liu] fix substringIndex
f2d29a1 [Davies Liu] Merge branch 'master' of github.com:apache/spark into str_index
515519b [zhichao.li] add foldable and remove null checking
9546991 [zhichao.li] scala style
67c253a [zhichao.li] hide some apis and clean code
b19b013 [zhichao.li] add codegen and clean code
ac863e9 [zhichao.li] reduce the calling of numChars
12e108f [zhichao.li] refine unittest
d92951b [zhichao.li] add lastIndexOf
52d7b03 [zhichao.li] add substring_index function

This PR brings SQL function soundex(), see https://issues.apache.org/jira/browse/HIVE-9738

It's based on #7115 , thanks to HuJiayin

Author: HuJiayin <jiayin.hu@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7812 from davies/soundex and squashes the following commits:

fa75941 [Davies Liu] Merge branch 'master' of github.com:apache/spark into soundex
a4bd6d8 [Davies Liu] fix soundex
2538908 [HuJiayin] add codegen soundex
d15d329 [HuJiayin] add back ut
ded1a14 [HuJiayin] Merge branch 'master' of https://github.com/apache/spark
e2dec2c [HuJiayin] support soundex rebase code

This PR adds the Python API for Kinesis, including a Python example and a simple unit test.

Author: zsxwing <zsxwing@gmail.com>

Closes #6955 from zsxwing/kinesis-python and squashes the following commits:

e42e471 [zsxwing] Merge branch 'master' into kinesis-python
455f7ea [zsxwing] Remove streaming_kinesis_asl_assembly module and simply add the source folder to streaming_kinesis_asl module
32e6451 [zsxwing] Merge remote-tracking branch 'origin/master' into kinesis-python
5082d28 [zsxwing] Fix the syntax error for Python 2.6
fca416b [zsxwing] Fix wrong comparison
96670ff [zsxwing] Fix the compilation error after merging master
756a128 [zsxwing] Merge branch 'master' into kinesis-python
6c37395 [zsxwing] Print stack trace for debug
7c5cfb0 [zsxwing] RUN_KINESIS_TESTS -> ENABLE_KINESIS_TESTS
cc9d071 [zsxwing] Fix the python test errors
466b425 [zsxwing] Add python tests for Kinesis
e33d505 [zsxwing] Merge remote-tracking branch 'origin/master' into kinesis-python
3da2601 [zsxwing] Fix the kinesis folder
687446b [zsxwing] Fix the error message and the maven output path
add2beb [zsxwing] Merge branch 'master' into kinesis-python
4957c0b [zsxwing] Add the Python API for Kinesis

support ml.NaiveBayes for Python

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #7568 from yanboliang/spark-9214 and squashes the following commits:

5ee3fd6 [Yanbo Liang] fix typos
3ecd046 [Yanbo Liang] fix typos
f9c94d1 [Yanbo Liang] change lambda_ to smoothing and fix other issues
180452a [Yanbo Liang] fix typos
7dda1f4 [Yanbo Liang] support ml.NaiveBayes for Python

Multiclass Classification Evaluator for ML Pipelines. F1 score, precision, recall, weighted precision and weighted recall are supported as available metrics.

Author: Ram Sriharsha <rsriharsha@hw11853.local>

Closes #7475 from harsha2010/SPARK-7690 and squashes the following commits:

9bf4ec7 [Ram Sriharsha] fix indentation
3f09a85 [Ram Sriharsha] cleanup doc
16115ae [Ram Sriharsha] code review fixes
032d2a3 [Ram Sriharsha] fix test
eec9865 [Ram Sriharsha] Fix Python Indentation
1dbeffd [Ram Sriharsha] Merge branch 'master' into SPARK-7690
68cea85 [Ram Sriharsha] Merge branch 'master' into SPARK-7690
54c03de [Ram Sriharsha] [SPARK-7690][ml][WIP] Multiclass Evaluator for ML Pipeline

This PR is based on #6988 , thanks to adrian-wang .

This brings two SQL functions: to_date() and trunc().

Closes #6988

Author: Daoyuan Wang <daoyuan.wang@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7805 from davies/to_date and squashes the following commits:

2c7beba [Davies Liu] Merge branch 'master' of github.com:apache/spark into to_date
310dd55 [Daoyuan Wang] remove dup test in rebase
980b092 [Daoyuan Wang] resolve rebase conflict
a476c5a [Daoyuan Wang] address comments from davies
d44ea5f [Daoyuan Wang] function to_date, trunc

This was previously committed but then reverted due to test failures (see #6769).

Author: Xiangrui Meng <meng@databricks.com>

Closes #7755 from rxin/SPARK-7157 and squashes the following commits:

fbf9044 [Xiangrui Meng] fix python test
542bd37 [Xiangrui Meng] update test
604fe6d [Xiangrui Meng] Merge remote-tracking branch 'apache/master' into SPARK-7157
f051afd [Xiangrui Meng] use udf instead of building expression
f4e9425 [Xiangrui Meng] Merge remote-tracking branch 'apache/master' into SPARK-7157
8fb990b [Xiangrui Meng] Merge remote-tracking branch 'apache/master' into SPARK-7157
103beb3 [Xiangrui Meng] add Java-friendly sampleBy
991f26f [Xiangrui Meng] fix seed
4a14834 [Xiangrui Meng] move sampleBy to stat
832f7cc [Xiangrui Meng] add sampleBy to DataFrame

This is based on MechCoder 's PR https://github.com/apache/spark/pull/7731. Hopefully it could pass tests. MechCoder I tried to make minimal changes. If this passes Jenkins, we can merge this one first and then try to move `__init__.py` to `local.py` in a separate PR.

Closes #7731

Author: Xiangrui Meng <meng@databricks.com>

Closes #7746 from mengxr/SPARK-9408 and squashes the following commits:

0e05a3b [Xiangrui Meng] merge master
1135551 [Xiangrui Meng] add a comment for str(...)
c48cae0 [Xiangrui Meng] update tests
173a805 [Xiangrui Meng] move linalg.py to linalg/__init__.py

[SPARK-8186] [SPARK-8187] [SPARK-8194] [SPARK-8198] [SPARK-9133] [SPARK-9290] [SQL] functions: date_add, date_sub, add_months, months_between, time-interval calculation

This PR is based on #7589 , thanks to adrian-wang

Added SQL function date_add, date_sub, add_months, month_between, also add a rule for
add/subtract of date/timestamp and interval.

Closes #7589

cc rxin

Author: Daoyuan Wang <daoyuan.wang@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7754 from davies/date_add and squashes the following commits:

e8c633a [Davies Liu] Merge branch 'master' of github.com:apache/spark into date_add
9e8e085 [Davies Liu] Merge branch 'master' of github.com:apache/spark into date_add
6224ce4 [Davies Liu] fix conclict
bd18cd4 [Davies Liu] Merge branch 'master' of github.com:apache/spark into date_add
e47ff2c [Davies Liu] add python api, fix date functions
01943d0 [Davies Liu] Merge branch 'master' into date_add
522e91a [Daoyuan Wang] fix
e8a639a [Daoyuan Wang] fix
42df486 [Daoyuan Wang] fix style
87c4b77 [Daoyuan Wang] function add_months, months_between and some fixes
1a68e03 [Daoyuan Wang] poc of time interval calculation
c506661 [Daoyuan Wang] function date_add , date_sub

This pull request enables Unsafe mode by default in Spark SQL. In order to do this, we had to fix a number of small issues:

**List of fixed blockers**:

- [x] Make some default buffer sizes configurable so that HiveCompatibilitySuite can run properly (#7741).
- [x] Memory leak on grouped aggregation of empty input (fixed by #7560 to fix this)
- [x] Update planner to also check whether codegen is enabled before planning unsafe operators.
- [x] Investigate failing HiveThriftBinaryServerSuite test.  This turns out to be caused by a ClassCastException that occurs when Exchange tries to apply an interpreted RowOrdering to an UnsafeRow when range partitioning an RDD.  This could be fixed by #7408, but a shorter-term fix is to just skip the Unsafe exchange path when RangePartitioner is used.
- [x] Memory leak exceptions masking exceptions that actually caused tasks to fail (will be fixed by #7603).
- [x]  ~~https://issues.apache.org/jira/browse/SPARK-9162, to implement code generation for ScalaUDF.  This is necessary for `UDFSuite` to pass.  For now, I've just ignored this test in order to try to find other problems while we wait for a fix.~~ This is no longer necessary as of #7682.
- [x] Memory leaks from Limit after UnsafeExternalSort cause the memory leak detector to fail tests. This is a huge problem in the HiveCompatibilitySuite (fixed by f4ac642a4e5b2a7931c5e04e086bb10e263b1db6).
- [x] Tests in `AggregationQuerySuite` are failing due to NaN-handling issues in UnsafeRow, which were fixed in #7736.
- [x] `org.apache.spark.sql.ColumnExpressionSuite.rand` needs to be updated so that the planner check also matches `TungstenProject`.
- [x] After having lowered the buffer sizes to 4MB so that most of HiveCompatibilitySuite runs:
  - [x] Wrong answer in `join_1to1` (fixed by #7680)
  - [x] Wrong answer in `join_nulls` (fixed by #7680)
  - [x] Managed memory OOM / leak in `lateral_view`
  - [x] Seems to hang indefinitely in `partcols1`.  This might be a deadlock in script transformation or a bug in error-handling code? The hang was fixed by #7710.
  - [x] Error while freeing memory in `partcols1`: will be fixed by #7734.
- [x] After fixing the `partcols1` hang, it appears that a number of later tests have issues as well.
- [x] Fix thread-safety bug in codegen fallback expression evaluation (#7759).

Author: Josh Rosen <joshrosen@databricks.com>

Closes #7564 from JoshRosen/unsafe-by-default and squashes the following commits:

83c0c56 [Josh Rosen] Merge remote-tracking branch 'origin/master' into unsafe-by-default
f4cc859 [Josh Rosen] Merge remote-tracking branch 'origin/master' into unsafe-by-default
963f567 [Josh Rosen] Reduce buffer size for R tests
d6986de [Josh Rosen] Lower page size in PySpark tests
013b9da [Josh Rosen] Also match TungstenProject in checkNumProjects
5d0b2d3 [Josh Rosen] Add task completion callback to avoid leak in limit after sort
ea250da [Josh Rosen] Disable unsafe Exchange path when RangePartitioning is used
715517b [Josh Rosen] Enable Unsafe by default

This is #7791 for Python. hhbyyh

Author: Xiangrui Meng <meng@databricks.com>

Closes #7798 from mengxr/regex-tok-py and squashes the following commits:

baa2dcd [Xiangrui Meng] fix doc for RegexTokenizer

Also we could create a Python UDT without having a Scala one, it's important for Python users.

cc mengxr JoshRosen

Author: Davies Liu <davies@databricks.com>

Closes #7453 from davies/class_in_main and squashes the following commits:

4dfd5e1 [Davies Liu] add tests for Python and Scala UDT
793d9b2 [Davies Liu] Merge branch 'master' of github.com:apache/spark into class_in_main
dc65f19 [Davies Liu] address comment
a9a3c40 [Davies Liu] Merge branch 'master' of github.com:apache/spark into class_in_main
a86e1fc [Davies Liu] fix serialization
ad528ba [Davies Liu] Merge branch 'master' of github.com:apache/spark into class_in_main
63f52ef [Davies Liu] fix pylint check
655b8a9 [Davies Liu] Merge branch 'master' of github.com:apache/spark into class_in_main
316a394 [Davies Liu] support Python UDT with UTF
0bcb3ef [Davies Liu] fix bug in mllib
de986d6 [Davies Liu] fix test
83d65ac [Davies Liu] fix bug in StructType
55bb86e [Davies Liu] support Python UDT in __main__ (without Scala one)

`names` is not defined in this context, I think you meant `self.names`.

davies

Author: Alex Angelini <alex.louis.angelini@gmail.com>

Closes #7766 from angelini/fix_struct_type_names and squashes the following commits:

01543a1 [Alex Angelini] Fix reference to self.names in StructType

Implement the classification trait for RandomForestClassifiers. The plan is to use this in the future to providing thresholding for RandomForestClassifiers (as well as other classifiers that implement that trait).

Author: Holden Karau <holden@pigscanfly.ca>

Closes #7432 from holdenk/SPARK-9016-make-random-forest-classifiers-implement-classification-trait and squashes the following commits:

bf22fa6 [Holden Karau] Add missing imports for testing suite
e948f0d [Holden Karau] Check the prediction generation from rawprediciton
25320c3 [Holden Karau] Don't supply numClasses when not needed, assert model classes are as expected
1a67e04 [Holden Karau] Use old decission tree stuff instead
673e0c3 [Holden Karau] Merge branch 'master' into SPARK-9016-make-random-forest-classifiers-implement-classification-trait
0d15b96 [Holden Karau] FIx typo
5eafad4 [Holden Karau] add a constructor for rootnode + num classes
fc6156f [Holden Karau] scala style fix
2597915 [Holden Karau] take num classes in constructor
3ccfe4a [Holden Karau] Merge in master, make pass numClasses through randomforest for training
222a10b [Holden Karau] Increase numtrees to 3 in the python test since before the two were equal and the argmax was selecting the last one
16aea1c [Holden Karau] Make tests match the new models
b454a02 [Holden Karau] Make the Tree classifiers extends the Classifier base class
77b4114 [Holden Karau] Import vectors lib

This PR introduces save / load for GMM's in python API.

Also I refactored `GaussianMixtureModel` and inherited it from `JavaModelWrapper` with model being `GaussianMixtureModelWrapper`, a wrapper which provides convenience methods to `GaussianMixtureModel` (due to serialization and deserialization issues) and I moved the creation of gaussians to the scala backend.

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7617 from MechCoder/python_gmm_save_load and squashes the following commits:

9c305aa [MechCoder] [SPARK-7105] [PySpark] [MLlib] Support model save/load in GMM

Author: JD <jd@csh.rit.edu>
Author: Joseph Batchik <josephbatchik@gmail.com>

Closes #7606 from JDrit/expr and squashes the following commits:

ad7f607 [Joseph Batchik] fixing python linter error
9d6daea [Joseph Batchik] removed order by per @rxin's comment
707d5c6 [Joseph Batchik] Added expr to fuctions.py
79df83c [JD] added example to the docs
b89eec8 [JD] moved function up as per @rxin's comment
4960909 [JD] updated per @JoshRosen's comment
2cb329c [JD] updated per @rxin's comment
9a9ad0c [JD] removing unused import
6dc26d0 [JD] removed split
7f2222c [JD] Adding expr function as per SPARK-8668

This is continuation of #7512 which added `--name` option to spark-shell. This PR adds the same option to pyspark.

Note that `--conf spark.app.name` in command-line has no effect in spark-shell and pyspark. Instead, `--name` must be used. This is in fact inconsistency with spark-sql which doesn't accept `--name` option while it accepts `--conf spark.app.name`. I am not fixing this inconsistency in this PR. IMO, one of `--name` and `--conf spark.app.name` is needed not both. But since I cannot decide which to choose, I am not making any change here.

Author: Cheolsoo Park <cheolsoop@netflix.com>

Closes #7610 from piaozhexiu/SPARK-9270 and squashes the following commits:

763e86d [Cheolsoo Park] Update windows script
400b7f9 [Cheolsoo Park] Allow --name option to pyspark

spark.mllib support batch predict for LinearRegressionModel, RidgeRegressionModel and LassoModel.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #7614 from yanboliang/spark-9122 and squashes the following commits:

4e610c0 [Yanbo Liang] spark.mllib regression support batch predict

Romove Decimal.Unlimited (change to support precision up to 38, to match with Hive and other databases).

In order to keep backward source compatibility, Decimal.Unlimited is still there, but change to Decimal(38, 18).

If no precision and scale is provide, it's Decimal(10, 0) as before.

Author: Davies Liu <davies@databricks.com>

Closes #7605 from davies/decimal_unlimited and squashes the following commits:

aa3f115 [Davies Liu] fix tests and style
fb0d20d [Davies Liu] address comments
bfaae35 [Davies Liu] fix style
df93657 [Davies Liu] address comments and clean up
06727fd [Davies Liu] Merge branch 'master' of github.com:apache/spark into decimal_unlimited
4c28969 [Davies Liu] fix tests
8d783cc [Davies Liu] fix tests
788631c [Davies Liu] fix double with decimal in Union/except
1779bde [Davies Liu] fix scala style
c9c7c78 [Davies Liu] remove Decimal.Unlimited

We forgot to update doc. brkyvz

Author: Xiangrui Meng <meng@databricks.com>

Closes #7608 from mengxr/SPARK-9243 and squashes the following commits:

0ea3236 [Xiangrui Meng] null -> zero in crosstab doc

Spark has an option called spark.localExecution.enabled; according to the docs:

> Enables Spark to run certain jobs, such as first() or take() on the driver, without sending tasks to the cluster. This can make certain jobs execute very quickly, but may require shipping a whole partition of data to the driver.

This feature ends up adding quite a bit of complexity to DAGScheduler, especially in the runLocallyWithinThread method, but as far as I know nobody uses this feature (I searched the mailing list and haven't seen any recent mentions of the configuration nor stacktraces including the runLocally method). As a step towards scheduler complexity reduction, I propose that we remove this feature and all code related to it for Spark 1.5.

This pull request simply brings #7484 up to date.

Author: Josh Rosen <joshrosen@databricks.com>
Author: Reynold Xin <rxin@databricks.com>

Closes #7585 from rxin/remove-local-exec and squashes the following commits:

84bd10e [Reynold Xin] Python fix.
1d9739a [Reynold Xin] Merge pull request #7484 from JoshRosen/remove-localexecution
eec39fa [Josh Rosen] Remove allowLocal(); deprecate user-facing uses of it.
b0835dc [Josh Rosen] Remove local execution code in DAGScheduler
8975d96 [Josh Rosen] Remove local execution tests.
ffa8c9b [Josh Rosen] Remove documentation for configuration

Since save / load has been merged in LDA, it takes no time to write the wrappers in Python as well.

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7587 from MechCoder/python_lda_save_load and squashes the following commits:

c8e4ea7 [MechCoder] [SPARK-9223] [PySpark] Support model save/load in LDA

There are a few memory limits that people hit often and that we could
make higher, especially now that memory sizes have grown.

- spark.akka.frameSize: This defaults at 10 but is often hit for map
  output statuses in large shuffles. This memory is not fully allocated
  up-front, so we can just make this larger and still not affect jobs
  that never sent a status that large. We increase it to 128.

- spark.executor.memory: Defaults at 512m, which is really small. We
  increase it to 1g.

Author: Matei Zaharia <matei@databricks.com>

Closes #7586 from mateiz/configs and squashes the following commits:

ce0038a [Matei Zaharia] [SPARK-9244] Increase some memory defaults

Pull Request for: https://issues.apache.org/jira/browse/SPARK-8230

Primary issue resolved is to implement array/map size for Spark SQL. Code is ready for review by a committer. Chen Hao is on the JIRA ticket, but I don't know his username on github, rxin is also on JIRA ticket.

Things to review:
1. Where to put added functions namespace wise, they seem to be part of a few operations on collections which includes `sort_array` and `array_contains`. Hence the name given `collectionOperations.scala` and `_collection_functions` in python.
2. In Python code, should it be in a `1.5.0` function array or in a collections array?
3. Are there any missing methods on the `Size` case class? Looks like many of these functions have generated Java code, is that also needed in this case?
4. Something else?

Author: Pedro Rodriguez <ski.rodriguez@gmail.com>
Author: Pedro Rodriguez <prodriguez@trulia.com>

Closes #7462 from EntilZha/SPARK-8230 and squashes the following commits:

9a442ae [Pedro Rodriguez] fixed functions and sorted __all__
9aea3bb [Pedro Rodriguez] removed imports from python docs
15d4bf1 [Pedro Rodriguez] Added null test case and changed to nullSafeCodeGen
d88247c [Pedro Rodriguez] removed python code
bd5f0e4 [Pedro Rodriguez] removed duplicate function from rebase/merge
59931b4 [Pedro Rodriguez] fixed compile bug instroduced when merging
c187175 [Pedro Rodriguez] updated code to add size to __all__ directly and removed redundent pretty print
130839f [Pedro Rodriguez] fixed failing test
aa9bade [Pedro Rodriguez] fix style
e093473 [Pedro Rodriguez] updated python code with docs, switched classes/traits implemented, added (failing) expression tests
0449377 [Pedro Rodriguez] refactored code to use better abstract classes/traits and implementations
9a1a2ff [Pedro Rodriguez] added unit tests for map size
2bfbcb6 [Pedro Rodriguez] added unit test for size
20df2b4 [Pedro Rodriguez] Finished working version of size function and added it to python
b503e75 [Pedro Rodriguez] First attempt at implementing size for maps and arrays
99a6a5c [Pedro Rodriguez] fixed failing test
cac75ac [Pedro Rodriguez] fix style
933d843 [Pedro Rodriguez] updated python code with docs, switched classes/traits implemented, added (failing) expression tests
42bb7d4 [Pedro Rodriguez] refactored code to use better abstract classes/traits and implementations
f9c3b8a [Pedro Rodriguez] added unit tests for map size
2515d9f [Pedro Rodriguez] added documentation
0e60541 [Pedro Rodriguez] added unit test for size
acf9853 [Pedro Rodriguez] Finished working version of size function and added it to python
84a5d38 [Pedro Rodriguez] First attempt at implementing size for maps and arrays

Add expressions `regex_extract` & `regex_replace`

Author: Cheng Hao <hao.cheng@intel.com>

Closes #7468 from chenghao-intel/regexp and squashes the following commits:

e5ea476 [Cheng Hao] minor update for documentation
ef96fd6 [Cheng Hao] update the code gen
72cf28f [Cheng Hao] Add more log for compilation error
4e11381 [Cheng Hao] Add regexp_replace / regexp_extract support

This PR adds DataFrame reader/writer shortcut methods for ORC in both Scala and Python.

Author: Cheng Lian <lian@databricks.com>

Closes #7444 from liancheng/spark-9100 and squashes the following commits:

284d043 [Cheng Lian] Fixes PySpark test cases and addresses PR comments
e0b09fb [Cheng Lian] Adds DataFrame reader/writer shortcut methods for ORC

Several places in the PySpark SparseVector docs have one defined as:
```
SparseVector(4, [2, 4], [1.0, 2.0])
```
The index 4 goes out of bounds (but this is not checked).

CC: mengxr

Author: Joseph K. Bradley <joseph@databricks.com>

Closes #7541 from jkbradley/sparsevec-doc-typo-fix and squashes the following commits:

c806a65 [Joseph K. Bradley] fixed doc test
e2dcb23 [Joseph K. Bradley] Fixed typo in pyspark sparsevector doc tests

This PR also remove the duplicated code between registerFunction and UserDefinedFunction.

cc JoshRosen

Author: Davies Liu <davies@databricks.com>

Closes #7450 from davies/fix_return_type and squashes the following commits:

e80bf9f [Davies Liu] remove debugging code
f94b1f6 [Davies Liu] fix mima
8f9c58b [Davies Liu] convert returned object from UDF into internal type

JIRA: https://issues.apache.org/jira/browse/SPARK-9101

Author: Mateusz Buśkiewicz <mateusz.buskiewicz@getbase.com>

Closes #7499 from sixers/spark-9101 and squashes the following commits:

dd75aa6 [Mateusz Buśkiewicz] [SPARK-9101] [PySpark] Test for selecting null literal
97e3f2f [Mateusz Buśkiewicz] [SPARK-9101] [PySpark] Add missing NullType to _atomic_types in pyspark.sql.types

Python API for the KS-test

Statistics.kolmogorovSmirnovTest(data, distName, *params)
I'm not quite sure how to support the callable function since it is not serializable.

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7430 from MechCoder/spark-8996 and squashes the following commits:

2dd009d [MechCoder] minor
021d233 [MechCoder] Remove one wrapper and other minor stuff
49d07ab [MechCoder] [SPARK-8996] [MLlib] Python API for Kolmogorov-Smirnov Test

[SPARK-9021] [PYSPARK] Change RDD.aggregate() to do reduce(mapPartitions()) instead of mapPartitions.fold()

I'm relatively new to Spark and functional programming, so forgive me if this pull request is just a result of my misunderstanding of how Spark should be used.

Currently, if one happens to use a mutable object as `zeroValue` for `RDD.aggregate()`, possibly unexpected behavior can occur.

This is because pyspark's current implementation of `RDD.aggregate()` does not serialize or make a copy of `zeroValue` before handing it off to `RDD.mapPartitions(...).fold(...)`. This results in a single reference to `zeroValue` being used for both `RDD.mapPartitions()` and `RDD.fold()` on each partition. This can result in strange accumulator values being fed into each partition's call to `RDD.fold()`, as the `zeroValue` may have been changed in-place during the `RDD.mapPartitions()` call.

As an illustrative example, submit the following to `spark-submit`:
```
from pyspark import SparkConf, SparkContext
import collections

def updateCounter(acc, val):
    print 'update acc:', acc
    print 'update val:', val
    acc[val] += 1
    return acc

def comboCounter(acc1, acc2):
    print 'combo acc1:', acc1
    print 'combo acc2:', acc2
    acc1.update(acc2)
    return acc1

def main():
    conf = SparkConf().setMaster("local").setAppName("Aggregate with Counter")
    sc = SparkContext(conf = conf)

    print '======= AGGREGATING with ONE PARTITION ======='
    print sc.parallelize(range(1,10), 1).aggregate(collections.Counter(), updateCounter, comboCounter)

    print '======= AGGREGATING with TWO PARTITIONS ======='
    print sc.parallelize(range(1,10), 2).aggregate(collections.Counter(), updateCounter, comboCounter)

if __name__ == "__main__":
    main()
```

One probably expects this to output the following:
```
Counter({1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1, 7: 1, 8: 1, 9: 1})
```

But it instead outputs this (regardless of the number of partitions):
```
Counter({1: 2, 2: 2, 3: 2, 4: 2, 5: 2, 6: 2, 7: 2, 8: 2, 9: 2})
```

This is because (I believe) `zeroValue` gets passed correctly to each partition, but after `RDD.mapPartitions()` completes, the `zeroValue` object has been updated and is then passed to `RDD.fold()`, which results in all items being double-counted within each partition before being finally reduced at the calling node.

I realize that this type of calculation is typically done by `RDD.mapPartitions(...).reduceByKey(...)`, but hopefully this illustrates some potentially confusing behavior. I also noticed that other `RDD` methods use this `deepcopy` approach to creating unique copies of `zeroValue` (i.e., `RDD.aggregateByKey()` and `RDD.foldByKey()`), and that the Scala implementations do seem to serialize the `zeroValue` object appropriately to prevent this type of behavior.

Author: Nicholas Hwang <moogling@gmail.com>

Closes #7378 from njhwang/master and squashes the following commits:

659bb27 [Nicholas Hwang] Fixed RDD.aggregate() to perform a reduce operation on collected mapPartitions results, similar to how fold currently is implemented. This prevents an initial combOp being performed on each partition with zeroValue (which leads to unexpected behavior if zeroValue is a mutable object) before being combOp'ed with other partition results.
8d8d694 [Nicholas Hwang] Changed dict construction to be compatible with Python 2.6 (cannot use list comprehensions to make dicts)
56eb2ab [Nicholas Hwang] Fixed whitespace after colon to conform with PEP8
391de4a [Nicholas Hwang] Removed used of collections.Counter from RDD tests for Python 2.6 compatibility; used defaultdict(int) instead. Merged treeAggregate test with mutable zero value into aggregate test to reduce code duplication.
2fa4e4b [Nicholas Hwang] Merge branch 'master' of https://github.com/njhwang/spark
ba528bd [Nicholas Hwang] Updated comments regarding protection of zeroValue from mutation in RDD.aggregate(). Added regression tests for aggregate(), fold(), aggregateByKey(), foldByKey(), and treeAggregate(), all with both 1 and 2 partition RDDs. Confirmed that aggregate() is the only problematic implementation as of commit 257236c3. Also replaced some parallelizations of ranges with xranges, per the documentation's recommendations of preferring xrange over range.
7820391 [Nicholas Hwang] Updated comments regarding protection of zeroValue from mutation in RDD.aggregate(). Added regression tests for aggregate(), fold(), aggregateByKey(), foldByKey(), and treeAggregate(), all with both 1 and 2 partition RDDs. Confirmed that aggregate() is the only problematic implementation as of commit 257236c3.
90d1544 [Nicholas Hwang] Made sure RDD.aggregate() makes a deepcopy of zeroValue for all partitions; this ensures that the mapPartitions call works with unique copies of zeroValue in each partition, and prevents a single reference to zeroValue being used for both map and fold calls on each partition (resulting in possibly unexpected behavior).

This pull request fixes some of the problems in #6981.

- Added date functions to `__all__` so they get exposed
- Rename day_of_month -> dayofmonth
- Rename day_in_year -> dayofyear
- Rename week_of_year -> weekofyear
- Removed "day" from Scala/Python API since it is ambiguous. Only leaving the alias in SQL.

Author: Reynold Xin <rxin@databricks.com>

This patch had conflicts when merged, resolved by
Committer: Reynold Xin <rxin@databricks.com>

Closes #7506 from rxin/datetime and squashes the following commits:

0cb24d9 [Reynold Xin] Export all functions in Python.
e44a4a0 [Reynold Xin] Removed day function from Scala and Python.
9c08fdc [Reynold Xin] [SQL] Make date/time functions more consistent with other database systems.

JIRA: https://issues.apache.org/jira/browse/SPARK-9166

Simply capture and hide `IllegalArgumentException` in Python API.

Author: Liang-Chi Hsieh <viirya@appier.com>

Closes #7497 from viirya/hide_illegalargument and squashes the following commits:

8324dce [Liang-Chi Hsieh] Fix python style.
9ace67d [Liang-Chi Hsieh] Also check exception message.
8b2ce5c [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into hide_illegalargument
7be016a [Liang-Chi Hsieh] Capture and hide IllegalArgumentException in Python.

[SPARK-8199][SPARK-8184][SPARK-8183][SPARK-8182][SPARK-8181][SPARK-8180][SPARK-8179][SPARK-8177][SPARK-8178][SPARK-9115][SQL] date functions

Jira:
https://issues.apache.org/jira/browse/SPARK-8199
https://issues.apache.org/jira/browse/SPARK-8184
https://issues.apache.org/jira/browse/SPARK-8183
https://issues.apache.org/jira/browse/SPARK-8182
https://issues.apache.org/jira/browse/SPARK-8181
https://issues.apache.org/jira/browse/SPARK-8180
https://issues.apache.org/jira/browse/SPARK-8179
https://issues.apache.org/jira/browse/SPARK-8177
https://issues.apache.org/jira/browse/SPARK-8179
https://issues.apache.org/jira/browse/SPARK-9115

Regarding `day`and `dayofmonth` are both necessary?

~~I am going to add `Quarter` to this PR as well.~~ Done.

~~As soon as the Scala coding is reviewed and discussed, I'll add the python api.~~ Done

Author: Tarek Auel <tarek.auel@googlemail.com>
Author: Tarek Auel <tarek.auel@gmail.com>

Closes #6981 from tarekauel/SPARK-8199 and squashes the following commits:

f7b4c8c [Tarek Auel] [SPARK-8199] fixed bug in tests
bb567b6 [Tarek Auel] [SPARK-8199] fixed test
3e095ba [Tarek Auel] [SPARK-8199] style and timezone fix
256c357 [Tarek Auel] [SPARK-8199] code cleanup
5983dcc [Tarek Auel] [SPARK-8199] whitespace fix
6e0c78f [Tarek Auel] [SPARK-8199] removed setTimeZone in tests, according to cloud-fans comment in #7488
4afc09c [Tarek Auel] [SPARK-8199] concise leap year handling
ea6c110 [Tarek Auel] [SPARK-8199] fix after merging master
70238e0 [Tarek Auel] Merge branch 'master' into SPARK-8199
3c6ae2e [Tarek Auel] [SPARK-8199] removed binary search
fb98ba0 [Tarek Auel] [SPARK-8199] python docstring fix
cdfae27 [Tarek Auel] [SPARK-8199] cleanup & python docstring fix
746b80a [Tarek Auel] [SPARK-8199] build fix
0ad6db8 [Tarek Auel] [SPARK-8199] minor fix
523542d [Tarek Auel] [SPARK-8199] address comments
2259299 [Tarek Auel] [SPARK-8199] day_of_month alias
d01b977 [Tarek Auel] [SPARK-8199] python underscore
56c4a92 [Tarek Auel] [SPARK-8199] update python docu
e223bc0 [Tarek Auel] [SPARK-8199] refactoring
d6aa14e [Tarek Auel] [SPARK-8199] fixed Hive compatibility
b382267 [Tarek Auel] [SPARK-8199] fixed bug in day calculation; removed set TimeZone in HiveCompatibilitySuite for test purposes; removed Hive tests for second and minute, because we can cast '2015-03-18' to a timestamp and extract a minute/second from it
1b2e540 [Tarek Auel] [SPARK-8119] style fix
0852655 [Tarek Auel] [SPARK-8119] changed from ExpectsInputTypes to implicit casts
ec87c69 [Tarek Auel] [SPARK-8119] bug fixing and refactoring
1358cdc [Tarek Auel] Merge remote-tracking branch 'origin/master' into SPARK-8199
740af0e [Tarek Auel] implement date function using a calculation based on days
4fb66da [Tarek Auel] WIP: date functions on calculation only
1a436c9 [Tarek Auel] wip
f775f39 [Tarek Auel] fixed return type
ad17e96 [Tarek Auel] improved implementation
c42b444 [Tarek Auel] Removed merge conflict file
ccb723c [Tarek Auel] [SPARK-8199] style and fixed merge issues
10e4ad1 [Tarek Auel] Merge branch 'master' into date-functions-fast
7d9f0eb [Tarek Auel] [SPARK-8199] git renaming issue
f3e7a9f [Tarek Auel] [SPARK-8199] revert change in DataFrameFunctionsSuite
6f5d95c [Tarek Auel] [SPARK-8199] fixed year interval
d9f8ac3 [Tarek Auel] [SPARK-8199] implement fast track
7bc9d93 [Tarek Auel] Merge branch 'master' into SPARK-8199
5a105d9 [Tarek Auel] [SPARK-8199] rebase after #6985 got merged
eb6760d [Tarek Auel] Merge branch 'master' into SPARK-8199
f120415 [Tarek Auel] improved runtime
a8edebd [Tarek Auel] use Calendar instead of SimpleDateFormat
5fe74e1 [Tarek Auel] fixed python style
3bfac90 [Tarek Auel] fixed style
356df78 [Tarek Auel] rely on cast mechanism of Spark. Simplified implementation
02efc5d [Tarek Auel] removed doubled code
a5ea120 [Tarek Auel] added python api; changed test to be more meaningful
b680db6 [Tarek Auel] added codegeneration to all functions
c739788 [Tarek Auel] added support for quarter SPARK-8178
849fb41 [Tarek Auel] fixed stupid test
638596f [Tarek Auel] improved codegen
4d8049b [Tarek Auel] fixed tests and added type check
5ebb235 [Tarek Auel] resolved naming conflict
d0e2f99 [Tarek Auel] date functions

I Implemented the KMeans API for spark.ml Pipelines. But it doesn't include clustering abstractions for spark.ml (SPARK-7610). It would fit for another issues. And I'll try it later, since we are trying to add the hierarchical clustering algorithms in another issue. Thanks.

[SPARK-7879] KMeans API for spark.ml Pipelines - ASF JIRA https://issues.apache.org/jira/browse/SPARK-7879

Author: Yu ISHIKAWA <yuu.ishikawa@gmail.com>

Closes #6756 from yu-iskw/SPARK-7879 and squashes the following commits:

be752de [Yu ISHIKAWA] Add assertions
a14939b [Yu ISHIKAWA] Fix the dashed line's length in pyspark.ml.rst
4c61693 [Yu ISHIKAWA] Remove the test about whether "features" and "prediction" columns exist or not in Python
fb2417c [Yu ISHIKAWA] Use getInt, instead of get
f397be4 [Yu ISHIKAWA] Switch the comparisons.
ca78b7d [Yu ISHIKAWA] Add the Scala docs about the constraints of each parameter.
effc650 [Yu ISHIKAWA] Using expertSetParam and expertGetParam
c8dc6e6 [Yu ISHIKAWA] Remove an unnecessary test
19a9d63 [Yu ISHIKAWA] Include spark.ml.clustering to python tests
1abb19c [Yu ISHIKAWA] Add the statements about spark.ml.clustering into pyspark.ml.rst
f8338bc [Yu ISHIKAWA] Add the placeholders in Python
4a03003 [Yu ISHIKAWA] Test for contains in Python
6566c8b [Yu ISHIKAWA] Use `get`, instead of `apply`
288e8d5 [Yu ISHIKAWA] Using `contains` to check the column names
5a7d574 [Yu ISHIKAWA] Renamce `validateInitializationMode` to `validateInitMode` and remove throwing exception
97cfae3 [Yu ISHIKAWA] Fix the type of return value of `KMeans.copy`
e933723 [Yu ISHIKAWA] Remove the default value of seed from the Model class
978ee2c [Yu ISHIKAWA] Modify the docs of KMeans, according to mllib's KMeans
2ec80bc [Yu ISHIKAWA] Fit on 1 line
e186be1 [Yu ISHIKAWA] Make a few variables, setters and getters be expert ones
b2c205c [Yu ISHIKAWA] Rename the method `getInitializationSteps` to `getInitSteps` and `setInitializationSteps` to `setInitSteps` in Scala and Python
f43f5b4 [Yu ISHIKAWA] Rename the method `getInitializationMode` to `getInitMode` and `setInitializationMode` to `setInitMode` in Scala and Python
3cb5ba4 [Yu ISHIKAWA] Modify the description about epsilon and the validation
4fa409b [Yu ISHIKAWA] Add a comment about the default value of epsilon
2f392e1 [Yu ISHIKAWA] Make some variables `final` and Use `IntParam` and `DoubleParam`
19326f8 [Yu ISHIKAWA] Use `udf`, instead of callUDF
4d2ad1e [Yu ISHIKAWA] Modify the indentations
0ae422f [Yu ISHIKAWA] Add a test for `setParams`
4ff7913 [Yu ISHIKAWA] Add "ml.clustering" to `javacOptions` in SparkBuild.scala
11ffdf1 [Yu ISHIKAWA] Use `===` and the variable
220a176 [Yu ISHIKAWA] Set a random seed in the unit testing
92c3efc [Yu ISHIKAWA] Make the points for a test be fewer
c758692 [Yu ISHIKAWA] Modify the parameters of KMeans in Python
6aca147 [Yu ISHIKAWA] Add some unit testings to validate the setter methods
687cacc [Yu ISHIKAWA] Alias mllib.KMeans as MLlibKMeans in KMeansSuite.scala
a4dfbef [Yu ISHIKAWA] Modify the last brace and indentations
5bedc51 [Yu ISHIKAWA] Remve an extra new line
444c289 [Yu ISHIKAWA] Add the validation for `runs`
e41989c [Yu ISHIKAWA] Modify how to validate `initStep`
7ea133a [Yu ISHIKAWA] Change how to validate `initMode`
7991e15 [Yu ISHIKAWA] Add a validation for `k`
c2df35d [Yu ISHIKAWA] Make `predict` private
93aa2ff [Yu ISHIKAWA] Use `withColumn` in `transform`
d3a79f7 [Yu ISHIKAWA] Remove the inhefited docs
e9532e1 [Yu ISHIKAWA] make `parentModel` of KMeansModel private
8559772 [Yu ISHIKAWA] Remove the `paramMap` parameter of KMeans
6684850 [Yu ISHIKAWA] Rename `initializationSteps` to `initSteps`
99b1b96 [Yu ISHIKAWA] Rename `initializationMode` to `initMode`
79ea82b [Yu ISHIKAWA] Modify the parameters of KMeans docs
6569bcd [Yu ISHIKAWA] Change how to set the default values with `setDefault`
20a795a [Yu ISHIKAWA] Change how to set the default values with `setDefault`
11c2a12 [Yu ISHIKAWA] Limit the imports
badb481 [Yu ISHIKAWA] Alias spark.mllib.{KMeans, KMeansModel}
f80319a [Yu ISHIKAWA] Rebase mater branch and add copy methods
85d92b1 [Yu ISHIKAWA] Add `KMeans.setPredictionCol`
aa9469d [Yu ISHIKAWA] Fix a python test suite error caused by python 3.x
c2d6bcb [Yu ISHIKAWA] ADD Java test suites of the KMeans API for spark.ml Pipeline
598ed2e [Yu ISHIKAWA] Implement the KMeans API for spark.ml Pipelines in Python
63ad785 [Yu ISHIKAWA] Implement the KMeans API for spark.ml Pipelines in Scala