## What changes were proposed in this pull request?
Document Dataset.union is resolution by position, not by name, since this has been a confusing point for a lot of users.

## How was this patch tested?
N/A - doc only change.

Author: Reynold Xin <rxin@databricks.com>

Closes #18256 from rxin/SPARK-21042.

## What changes were proposed in this pull request?

Allow fill/replace of NAs with booleans, both in Python and Scala

## How was this patch tested?

Unit tests, doctests

This PR is original work from me and I license this work to the Spark project

Author: Ruben Berenguel Montoro <ruben@mostlymaths.net>
Author: Ruben Berenguel <ruben@mostlymaths.net>

Closes #18164 from rberenguel/SPARK-19732-fillna-bools.

### What changes were proposed in this pull request?
This PR does the following tasks:
- Added  since
- Added the Python API
- Added test cases

### How was this patch tested?
Added test cases to both Scala and Python

Author: gatorsmile <gatorsmile@gmail.com>

Closes #18147 from gatorsmile/createOrReplaceGlobalTempView.

## What changes were proposed in this pull request?

PySpark supports stringIndexerOrderType in RFormula as in #17967.

## How was this patch tested?
docstring test

Author: actuaryzhang <actuaryzhang10@gmail.com>

Closes #18122 from actuaryzhang/PythonRFormula.

Now that Structured Streaming has been out for several Spark release and has large production use cases, the `Experimental` label is no longer appropriate.  I've left `InterfaceStability.Evolving` however, as I think we may make a few changes to the pluggable Source & Sink API in Spark 2.3.

Author: Michael Armbrust <michael@databricks.com>

Closes #18065 from marmbrus/streamingGA.

## What changes were proposed in this pull request?

Expose numPartitions (expert) param of PySpark FPGrowth.

## How was this patch tested?

+ [x] Pass all unit tests.

Author: Yan Facai (颜发才) <facai.yan@gmail.com>

Closes #18058 from facaiy/ENH/pyspark_fpg_add_num_partition.

## What changes were proposed in this pull request?
Follow-up for #17218, some minor fix for PySpark ```FPGrowth```.

## How was this patch tested?
Existing UT.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #18089 from yanboliang/spark-19281.

## What changes were proposed in this pull request?

Fixed TypeError with python3 and numpy 1.12.1. Numpy's `reshape` no longer takes floats as arguments as of 1.12. Also, python3 uses float division for `/`, we should be using `//` to ensure that `_dataWithBiasSize` doesn't get set to a float.

## How was this patch tested?

Existing tests run using python3 and numpy 1.12.

Author: Bago Amirbekian <bago@databricks.com>

Closes #18081 from MrBago/BF-py3floatbug.

## What changes were proposed in this pull request?

- Fix incorrect tests for `_check_thresholds`.
- Move test to `ParamTests`.

## How was this patch tested?

Unit tests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #18085 from zero323/SPARK-20631-FOLLOW-UP.

[SPARK-20764][ML][PYSPARK][FOLLOWUP] Fix visibility discrepancy with numInstances and degreesOfFreedom in LR and GLR - Python version

## What changes were proposed in this pull request?
Add test cases for PR-18062

## How was this patch tested?
The existing UT

Author: Peng <peng.meng@intel.com>

Closes #18068 from mpjlu/moreTest.

Changes:

pyspark.ml Estimators can take either a list of param maps or a dict of params. This change allows the CrossValidator and TrainValidationSplit Estimators to pass through lists of param maps to the underlying estimators so that those estimators can handle parallelization when appropriate (eg distributed hyper parameter tuning).

Testing:

Existing unit tests.

Author: Bago Amirbekian <bago@databricks.com>

Closes #18077 from MrBago/delegate_params.

[SPARK-20764][ML][PYSPARK] Fix visibility discrepancy with numInstances and degreesOfFreedom in LR and GLR - Python version

## What changes were proposed in this pull request?

SPARK-20097 exposed degreesOfFreedom in LinearRegressionSummary and numInstances in GeneralizedLinearRegressionSummary. Python API should be updated to reflect these changes.

## How was this patch tested?
The existing UT

Author: Peng <peng.meng@intel.com>

Closes #18062 from mpjlu/spark-20764.

## What changes were proposed in this pull request?
PySpark StringIndexer supports StringOrderType added in #17879.

Author: Wayne Zhang <actuaryzhang@uber.com>

Closes #17978 from actuaryzhang/PythonStringIndexer.

## What changes were proposed in this pull request?
Review new Scala APIs introduced in 2.2.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17934 from yanboliang/spark-20501.

## What changes were proposed in this pull request?
Before 2.2, MLlib keep to remove APIs deprecated in last feature/minor release. But from Spark 2.2, we decide to remove deprecated APIs in a major release, so we need to change corresponding annotations to tell users those will be removed in 3.0.
Meanwhile, this fixed bugs in ML documents. The original ML docs can't show deprecated annotations in ```MLWriter``` and ```MLReader``` related class, we correct it in this PR.

Before:
![image](https://cloud.githubusercontent.com/assets/1962026/25939889/f8c55f20-3666-11e7-9fa2-0605bfb3ed06.png)

After:
![image](https://cloud.githubusercontent.com/assets/1962026/25939870/e9b0d5be-3666-11e7-9765-5e04885e4b32.png)

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17946 from yanboliang/spark-20707.

[SPARK-20639][SQL] Add single argument support for to_timestamp in SQL with documentation improvement

## What changes were proposed in this pull request?

This PR proposes three things as below:

- Use casting rules to a timestamp in `to_timestamp` by default (it was `yyyy-MM-dd HH:mm:ss`).

- Support single argument for `to_timestamp` similarly with APIs in other languages.

  For example, the one below works

  ```
  import org.apache.spark.sql.functions._
  Seq("2016-12-31 00:12:00.00").toDF("a").select(to_timestamp(col("a"))).show()
  ```

  prints

  ```
  +----------------------------------------+
  |to_timestamp(`a`, 'yyyy-MM-dd HH:mm:ss')|
  +----------------------------------------+
  |                     2016-12-31 00:12:00|
  +----------------------------------------+
  ```

  whereas this does not work in SQL.

  **Before**

  ```
  spark-sql> SELECT to_timestamp('2016-12-31 00:12:00');
  Error in query: Invalid number of arguments for function to_timestamp; line 1 pos 7
  ```

  **After**

  ```
  spark-sql> SELECT to_timestamp('2016-12-31 00:12:00');
  2016-12-31 00:12:00
  ```

- Related document improvement for SQL function descriptions and other API descriptions accordingly.

  **Before**

  ```
  spark-sql> DESCRIBE FUNCTION extended to_date;
  ...
  Usage: to_date(date_str, fmt) - Parses the `left` expression with the `fmt` expression. Returns null with invalid input.
  Extended Usage:
      Examples:
        > SELECT to_date('2016-12-31', 'yyyy-MM-dd');
         2016-12-31
  ```

  ```
  spark-sql> DESCRIBE FUNCTION extended to_timestamp;
  ...
  Usage: to_timestamp(timestamp, fmt) - Parses the `left` expression with the `format` expression to a timestamp. Returns null with invalid input.
  Extended Usage:
      Examples:
        > SELECT to_timestamp('2016-12-31', 'yyyy-MM-dd');
         2016-12-31 00:00:00.0
  ```

  **After**

  ```
  spark-sql> DESCRIBE FUNCTION extended to_date;
  ...
  Usage:
      to_date(date_str[, fmt]) - Parses the `date_str` expression with the `fmt` expression to
        a date. Returns null with invalid input. By default, it follows casting rules to a date if
        the `fmt` is omitted.

  Extended Usage:
      Examples:
        > SELECT to_date('2009-07-30 04:17:52');
         2009-07-30
        > SELECT to_date('2016-12-31', 'yyyy-MM-dd');
         2016-12-31
  ```

  ```
  spark-sql> DESCRIBE FUNCTION extended to_timestamp;
  ...
   Usage:
      to_timestamp(timestamp[, fmt]) - Parses the `timestamp` expression with the `fmt` expression to
        a timestamp. Returns null with invalid input. By default, it follows casting rules to
        a timestamp if the `fmt` is omitted.

  Extended Usage:
      Examples:
        > SELECT to_timestamp('2016-12-31 00:12:00');
         2016-12-31 00:12:00
        > SELECT to_timestamp('2016-12-31', 'yyyy-MM-dd');
         2016-12-31 00:00:00
  ```

## How was this patch tested?

Added tests in `datetime.sql`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17901 from HyukjinKwon/to_timestamp_arg.

## What changes were proposed in this pull request?
This pr supported a DDL-formatted string in `DataFrameReader.schema`.
This fix could make users easily define a schema without importing  `o.a.spark.sql.types._`.

## How was this patch tested?
Added tests in `DataFrameReaderWriterSuite`.

Author: Takeshi Yamamuro <yamamuro@apache.org>

Closes #17719 from maropu/SPARK-20431.

This reverts commit b8733e0a.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17944 from yanboliang/spark-20606-revert.

## What changes were proposed in this pull request?

There's a latent corner-case bug in PySpark UDF evaluation where executing a `BatchPythonEvaluation` with a single multi-argument UDF where _at least one argument value is repeated_ will crash at execution with a confusing error.

This problem was introduced in #12057: the code there has a fast path for handling a "batch UDF evaluation consisting of a single Python UDF", but that branch incorrectly assumes that a single UDF won't have repeated arguments and therefore skips the code for unpacking arguments from the input row (whose schema may not necessarily match the UDF inputs due to de-duplication of repeated arguments which occurred in the JVM before sending UDF inputs to Python).

This fix here is simply to remove this special-casing: it turns out that the code in the "multiple UDFs" branch just so happens to work for the single-UDF case because Python treats `(x)` as equivalent to `x`, not as a single-argument tuple.

## How was this patch tested?

New regression test in `pyspark.python.sql.tests` module (tested and confirmed that it fails before my fix).

Author: Josh Rosen <joshrosen@databricks.com>

Closes #17927 from JoshRosen/SPARK-20685.

## What changes were proposed in this pull request?

It turns out pyspark doctest is calling saveAsTable without ever dropping them. Since we have separate python tests for bucketed table, and there is no checking of results, there is really no need to run the doctest, other than leaving it as an example in the generated doc

## How was this patch tested?

Jenkins

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #17932 from felixcheung/pytablecleanup.

[SPARK-20631][PYTHON][ML] LogisticRegression._checkThresholdConsistency should use values not Params

## What changes were proposed in this pull request?

- Replace `getParam` calls with `getOrDefault` calls.
- Fix exception message to avoid unintended `TypeError`.
- Add unit tests

## How was this patch tested?

New unit tests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17891 from zero323/SPARK-20631.

## What changes were proposed in this pull request?
Remove ML methods we deprecated in 2.1.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17867 from yanboliang/spark-20606.

## What changes were proposed in this pull request?

Adds Python wrappers for `DataFrameWriter.bucketBy` and `DataFrameWriter.sortBy` ([SPARK-16931](https://issues.apache.org/jira/browse/SPARK-16931))

## How was this patch tested?

Unit tests covering new feature.

__Note__: Based on work of GregBowyer (f49b9a23468f7af32cb53d2b654272757c151725)

CC HyukjinKwon

Author: zero323 <zero323@users.noreply.github.com>
Author: Greg Bowyer <gbowyer@fastmail.co.uk>

Closes #17077 from zero323/SPARK-16931.

## What changes were proposed in this pull request?

- Move udf wrapping code from `functions.udf` to `functions.UserDefinedFunction`.
- Return wrapped udf from `catalog.registerFunction` and dependent methods.
- Update docstrings in `catalog.registerFunction` and `SQLContext.registerFunction`.
- Unit tests.

## How was this patch tested?

- Existing unit tests and docstests.
- Additional tests covering new feature.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17831 from zero323/SPARK-18777.

## What changes were proposed in this pull request?

Adds `hint` method to PySpark `DataFrame`.

## How was this patch tested?

Unit tests, doctests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17850 from zero323/SPARK-20584.

## What changes were proposed in this pull request?

Use midpoints for split values now, and maybe later to make it weighted.

## How was this patch tested?

+ [x] add unit test.
+ [x] revise Split's unit test.

Author: Yan Facai (颜发才) <facai.yan@gmail.com>
Author: 颜发才（Yan Facai） <facai.yan@gmail.com>

Closes #17556 from facaiy/ENH/decision_tree_overflow_and_precision_in_aggregation.

Add PCA and SVD to PySpark's wrappers for `RowMatrix` and `IndexedRowMatrix` (SVD only).

Based on #7963, updated.

## How was this patch tested?

New doc tests and unit tests. Ran all examples locally.

Author: MechCoder <manojkumarsivaraj334@gmail.com>
Author: Nick Pentreath <nickp@za.ibm.com>

Closes #17621 from MLnick/SPARK-6227-pyspark-svd-pca.

Add Python API for `ALSModel` methods `recommendForAllUsers`, `recommendForAllItems`

## How was this patch tested?

New doc tests.

Author: Nick Pentreath <nickp@za.ibm.com>

Closes #17622 from MLnick/SPARK-20300-pyspark-recall.

## What changes were proposed in this pull request?

Adds Python bindings for `Column.eqNullSafe`

## How was this patch tested?

Manual tests, existing unit tests, doc build.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17605 from zero323/SPARK-20290.

## What changes were proposed in this pull request?

Currently pyspark Dataframe.fillna API supports boolean type when we pass dict, but it is missing in documentation.

## How was this patch tested?
>>> spark.createDataFrame([Row(a=True),Row(a=None)]).fillna({"a" : True}).show()
+----+
|   a|
+----+
|true|
|true|
+----+

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: Srinivasa Reddy Vundela <vsr@cloudera.com>

Closes #17688 from vundela/fillna_doc_fix.

## What changes were proposed in this pull request?

This PR proposes to fill up the documentation with examples for `bitwiseOR`, `bitwiseAND`, `bitwiseXOR`. `contains`, `asc` and `desc` in `Column` API.

Also, this PR fixes minor typos in the documentation and matches some of the contents between Scala doc and Python doc.

Lastly, this PR suggests to use `spark` rather than `sc` in doc tests in `Column` for Python documentation.

## How was this patch tested?

Doc tests were added and manually tested with the commands below:

`./python/run-tests.py --module pyspark-sql`
`./python/run-tests.py --module pyspark-sql --python-executable python3`
`./dev/lint-python`

Output was checked via `make html` under `./python/docs`. The snapshots will be left on the codes with comments.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17737 from HyukjinKwon/SPARK-20442.

## What changes were proposed in this pull request?
This pr added a new display mode for `Dataset.show` to print output rows vertically (one line per column value). In the current master, when printing Dataset with many columns, the readability is low like;

```
scala> val df = spark.range(100).selectExpr((0 until 100).map(i => s"rand() AS c$i"): _*)
scala> df.show(3, 0)
+------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+------------------+------------------+-------------------+------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+--------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+--------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+-------------------+------------------+-------------------+------------------+------------------+-----------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+------------------+-------------------+-------------------+------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+
|c0                |c1                |c2                |c3                 |c4                |c5                |c6                 |c7                |c8                |c9                |c10               |c11                |c12               |c13               |c14               |c15                |c16                |c17                |c18               |c19               |c20                |c21               |c22                |c23               |c24                |c25                |c26                |c27                 |c28                |c29               |c30                |c31                 |c32               |c33               |c34                |c35                |c36                |c37               |c38               |c39                |c40               |c41               |c42                |c43                |c44                |c45               |c46                 |c47                 |c48                |c49                |c50                |c51                |c52                |c53                |c54                 |c55                |c56                |c57                |c58                |c59               |c60               |c61                |c62                |c63               |c64                |c65               |c66               |c67              |c68                |c69                |c70               |c71                |c72               |c73                |c74                |c75                |c76               |c77                |c78               |c79                |c80                |c81                |c82                |c83                |c84                |c85                |c86                |c87               |c88                |c89                |c90               |c91               |c92               |c93                |c94               |c95                |c96               |c97                |c98                |c99                |
+------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+------------------+------------------+-------------------+------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+--------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+--------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+-------------------+------------------+-------------------+------------------+------------------+-----------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+------------------+-------------------+-------------------+------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+
|0.6306087152476858|0.9174349686288383|0.5511324165035159|0.3320844128641819 |0.7738486877101489|0.2154915886962553|0.4754997600674299 |0.922780639280355 |0.7136894772661909|0.2277580838165979|0.5926874459847249|0.40311408392226633|0.467830264333843 |0.8330466896984213|0.1893258482389527|0.6320849515511165 |0.7530911056912044 |0.06700254871955424|0.370528597355559 |0.2755437445193154|0.23704391110980128|0.8067400174905822|0.13597793616251852|0.1708888820162453|0.01672725007605702|0.983118121881555  |0.25040195628629924|0.060537253723083384|0.20000530582637488|0.3400572407133511|0.9375689433322597 |0.057039316954370256|0.8053269714347623|0.5247817572228813|0.28419308820527944|0.9798908885194533 |0.31805988175678146|0.7034448027077574|0.5400575751346084|0.25336322371116216|0.9361634546853429|0.6118681368289798|0.6295081549153907 |0.13417468943957422|0.41617137072255794|0.7267230869252035|0.023792726137561115|0.5776157058356362  |0.04884204913195467|0.26728716103441275|0.646680370807925  |0.9782712690657244 |0.16434031314818154|0.20985522381321275|0.24739842475440077 |0.26335189682977334|0.19604841662422068|0.10742950487300651|0.20283136488091502|0.3100312319723688|0.886959006630645 |0.25157102269776244|0.34428775168410786|0.3500506818575777|0.3781142441912052 |0.8560316444386715|0.4737104888956839|0.735903101602148|0.02236617130529006|0.8769074095835873 |0.2001426662503153|0.5534032319238532 |0.7289496620397098|0.41955191309992157|0.9337700133660436 |0.34059094378451005|0.6419144759403556|0.08167496930341167|0.9947099478497635|0.48010888605366586|0.22314796858167918|0.17786598882331306|0.7351521162297135 |0.5422057170020095 |0.9521927872726792 |0.7459825486368227 |0.40907708791990627|0.8903819313311575|0.7251413746923618 |0.2977174938745204 |0.9515209660203555|0.9375968604766713|0.5087851740042524|0.4255237544908751 |0.8023768698664653|0.48003189618006703|0.1775841829745185|0.09050775629268382|0.6743909291138167 |0.2498415755876865 |
|0.6866473844170801|0.4774360641212433|0.631696201340726 |0.33979113021468343|0.5663049010847052|0.7280190472258865|0.41370958502324806|0.9977433873622218|0.7671957338989901|0.2788708556233931|0.3355106391656496|0.88478952319287   |0.0333974166999893|0.6061744715862606|0.9617779139652359|0.22484954822341863|0.12770906021550898|0.5577789629508672 |0.2877649024640704|0.5566577406549361|0.9334933255278052 |0.9166720585157266|0.9689249324600591 |0.6367502457478598|0.7993572745928459 |0.23213222324218108|0.11928284054154137|0.6173493362456599  |0.0505122058694798 |0.9050228629552983|0.17112767911121707|0.47395598348370005 |0.5820498657823081|0.6241124650645072|0.18587258258036776|0.14987593554122225|0.3079446253653946 |0.9414228822867968|0.8362276265462365|0.9155655305576353 |0.5121559807153562|0.8963362656525707|0.22765970274318037|0.8177039187132797 |0.8190326635933787 |0.5256005177032199|0.8167598457269669  |0.030936807130934496|0.6733006585281015 |0.4208049626816347 |0.24603085738518538|0.22719198954208153|0.1622280557565281 |0.22217325159218038|0.014684419513742553|0.08987111517447499|0.2157764759142622 |0.8223414104088321 |0.4868624404491777 |0.4016191733088167|0.6169281906889263|0.15603611040433385|0.18289285085714913|0.9538408988218972|0.15037154865295121|0.5364516961987454|0.8077254873163031|0.712600478545675|0.7277477241003857 |0.19822912960348305|0.8305051199208777|0.18631911396566114|0.8909532487898342|0.3470409226992506 |0.35306974180587636|0.9107058868891469 |0.3321327206004986|0.48952332459050607|0.3630403307479373|0.5400046826340376 |0.5387377194310529 |0.42860539421837585|0.23214101630985995|0.21438968839794847|0.15370603160082352|0.04355605642700022|0.6096006707067466 |0.6933354157094292|0.06302172470859002|0.03174631856164001|0.664243581650643 |0.7833239547446621|0.696884598352864 |0.34626385933237736|0.9263495598791336|0.404818892816584  |0.2085585394755507|0.6150004897990109 |0.05391193524302473|0.28188484028329097|
+------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+------------------+------------------+-------------------+------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+--------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+--------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+-------------------+------------------+-------------------+------------------+------------------+-----------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+------------------+-------------------+-------------------+------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+
only showing top 2 rows
```

`psql`, CLI for PostgreSQL, supports a vertical display mode for this case like:
http://stackoverflow.com/questions/9604723/alternate-output-format-for-psql

```
-RECORD 0-------------------
 c0  | 0.6306087152476858
 c1  | 0.9174349686288383
 c2  | 0.5511324165035159
...
 c98 | 0.05391193524302473
 c99 | 0.28188484028329097
-RECORD 1-------------------
 c0  | 0.6866473844170801
 c1  | 0.4774360641212433
 c2  | 0.631696201340726
...
 c98 | 0.05391193524302473
 c99 | 0.28188484028329097
only showing top 2 rows
```

## How was this patch tested?
Added tests in `DataFrameSuite`.

Author: Takeshi Yamamuro <yamamuro@apache.org>

Closes #17733 from maropu/SPARK-20425.

## What changes were proposed in this pull request?
Some PySpark & SparkR tests run with tiny dataset and tiny ```maxIter```, which means they are not converged. I don’t think checking intermediate result during iteration make sense, and these intermediate result may vulnerable and not stable, so we should switch to check the converged result. We hit this issue at #17746 when we upgrade breeze to 0.13.1.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17757 from yanboliang/flaky-test.

## What changes were proposed in this pull request?
Upgrade breeze version to 0.13.1, which fixed some critical bugs of L-BFGS-B.

## How was this patch tested?
Existing unit tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17746 from yanboliang/spark-20449.

## What changes were proposed in this pull request?
Add docstrings to column.py for the Column functions `rlike`, `like`, `startswith`, and `endswith`. Pass these docstrings through `_bin_op`

There may be a better place to put the docstrings. I put them immediately above the Column class.

## How was this patch tested?

I ran `make html` on my local computer to remake the documentation, and verified that the html pages were displaying the docstrings correctly. I tried running `dev-tests`, and the formatting tests passed. However, my mvn build didn't work I think due to issues on my computer.

These docstrings are my original work and free license.

davies has done the most recent work reorganizing `_bin_op`

Author: Michael Patterson <map222@gmail.com>

Closes #17469 from map222/patterson-documentation.

## What changes were proposed in this pull request?

Establishes a very minimal `_repr_html_` for PySpark's `SparkContext`.

## How was this patch tested?

nteract:

![screen shot 2017-04-17 at 3 41 29 pm](https://cloud.githubusercontent.com/assets/836375/25107701/d57090ba-2385-11e7-8147-74bc2c50a41b.png)

Jupyter:

![screen shot 2017-04-17 at 3 53 19 pm](https://cloud.githubusercontent.com/assets/836375/25107725/05bf1fe8-2386-11e7-93e1-07a20c917dde.png)

Hydrogen:

![screen shot 2017-04-17 at 3 49 55 pm](https://cloud.githubusercontent.com/assets/836375/25107664/a75e1ddc-2385-11e7-8477-258661833007.png)

Author: Kyle Kelley <rgbkrk@gmail.com>

Closes #17662 from rgbkrk/repr.

## What changes were proposed in this pull request?

Improve combineByKey documentation:

* Add note on memory allocation
* Change example code to use different mergeValue and mergeCombiners

## How was this patch tested?

Doctest.

## Legal

This is my original work and I license the work to the project under the project’s open source license.

Author: David Gingrich <david@textio.com>

Closes #17545 from dgingrich/topic-spark-20232-combinebykey-docs.

## What changes were proposed in this pull request?

SPARK-15236 do this for scala shell, this ticket is for pyspark shell. This is not only for pyspark itself, but can also benefit downstream project like livy which use shell.py for its interactive session. For now, livy has no control of whether enable hive or not.

## How was this patch tested?

I didn't find a way to add test for it. Just manually test it.
Run `bin/pyspark --master local --conf spark.sql.catalogImplementation=in-memory` and verify hive is not enabled.

Author: Jeff Zhang <zjffdu@apache.org>

Closes #16906 from zjffdu/SPARK-19570.

## What changes were proposed in this pull request?

This PR proposes corrections related to JSON APIs as below:

- Rendering links in Python documentation
- Replacing `RDD` to `Dataset` in programing guide
- Adding missing description about JSON Lines consistently in `DataFrameReader.json` in Python API
- De-duplicating little bit of `DataFrameReader.json` in Scala/Java API

## How was this patch tested?

Manually build the documentation via `jekyll build`. Corresponding snapstops will be left on the codes.

Note that currently there are Javadoc8 breaks in several places. These are proposed to be handled in https://github.com/apache/spark/pull/17477. So, this PR does not fix those.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17602 from HyukjinKwon/minor-json-documentation.

## What changes were proposed in this pull request?

Added `util._message_exception` helper to use `str(e)` when `e.message` is unavailable (Python3).  Grepped for all occurrences of `.message` in `pyspark/` and these were the only occurrences.

## How was this patch tested?

- Doctests for helper function

## Legal

This is my original work and I license the work to the project under the project’s open source license.

Author: David Gingrich <david@textio.com>

Closes #16845 from dgingrich/topic-spark-19505-py3-exceptions.