## 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 wrappers for `o.a.s.sql.functions`:
- `split` as `split_string`
- `repeat` as `repeat_string`
## How was this patch tested?
Existing tests, additional unit tests, `check-cran.sh`
Author: zero323 <zero323@users.noreply.github.com>
Closes#17729 from zero323/SPARK-20438.
## What changes were proposed in this pull request?
Adds wrappers for `collect_list` and `collect_set`.
## How was this patch tested?
Unit tests, `check-cran.sh`
Author: zero323 <zero323@users.noreply.github.com>
Closes#17672 from zero323/SPARK-20371.
## What changes were proposed in this pull request?
Adds wrappers for `o.a.s.sql.functions.array` and `o.a.s.sql.functions.map`
## How was this patch tested?
Unit tests, `check-cran.sh`
Author: zero323 <zero323@users.noreply.github.com>
Closes#17674 from zero323/SPARK-20375.
## What changes were proposed in this pull request?
Checking a source parameter is asynchronous. When the query is created, it's not guaranteed that source has been created. This PR just increases the timeout of awaitTermination to ensure the parsing error is thrown.
## How was this patch tested?
Jenkins
Author: Shixiong Zhu <shixiong@databricks.com>
Closes#17687 from zsxwing/SPARK-20397.
## What changes were proposed in this pull request?
Document fpGrowth in:
- vignettes
- programming guide
- code example
## How was this patch tested?
Manual tests.
Author: zero323 <zero323@users.noreply.github.com>
Closes#17557 from zero323/SPARK-20208.
## What changes were proposed in this pull request?
This was suggested to be `as.json.array` at the first place in the PR to SPARK-19828 but we could not do this as the lint check emits an error for multiple dots in the variable names.
After SPARK-20278, now we are able to use `multiple.dots.in.names`. `asJsonArray` in `from_json` function is still able to be changed as 2.2 is not released yet.
So, this PR proposes to rename `asJsonArray` to `as.json.array`.
## How was this patch tested?
Jenkins tests, local tests with `./R/run-tests.sh` and manual `./dev/lint-r`. Existing tests should cover this.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17653 from HyukjinKwon/SPARK-19828-followup.
## What changes were proposed in this pull request?
Currently, multi-dot separated variables in R is not allowed. For example,
```diff
setMethod("from_json", signature(x = "Column", schema = "structType"),
- function(x, schema, asJsonArray = FALSE, ...) {
+ function(x, schema, as.json.array = FALSE, ...) {
if (asJsonArray) {
jschema <- callJStatic("org.apache.spark.sql.types.DataTypes",
"createArrayType",
```
produces an error as below:
```
R/functions.R:2462:31: style: Words within variable and function names should be separated by '_' rather than '.'.
function(x, schema, as.json.array = FALSE, ...) {
^~~~~~~~~~~~~
```
This seems against https://google.github.io/styleguide/Rguide.xml#identifiers which says
> The preferred form for variable names is all lower case letters and words separated with dots
This looks because lintr by default https://github.com/jimhester/lintr follows http://r-pkgs.had.co.nz/style.html as written in the README.md. Few cases seems not following Google's one as "a few tweaks".
Per [SPARK-6813](https://issues.apache.org/jira/browse/SPARK-6813), we follow Google's R Style Guide with few exceptions https://google.github.io/styleguide/Rguide.xml. This is also merged into Spark's website - https://github.com/apache/spark-website/pull/43
Also, it looks we have no limit on function name. This rule also looks affecting to the name of functions as written in the README.md.
> `multiple_dots_linter`: check that function and variable names are separated by _ rather than ..
## How was this patch tested?
Manually tested `./dev/lint-r`with the manual change below in `R/functions.R`:
```diff
setMethod("from_json", signature(x = "Column", schema = "structType"),
- function(x, schema, asJsonArray = FALSE, ...) {
+ function(x, schema, as.json.array = FALSE, ...) {
if (asJsonArray) {
jschema <- callJStatic("org.apache.spark.sql.types.DataTypes",
"createArrayType",
```
**Before**
```R
R/functions.R:2462:31: style: Words within variable and function names should be separated by '_' rather than '.'.
function(x, schema, as.json.array = FALSE, ...) {
^~~~~~~~~~~~~
```
**After**
```
lintr checks passed.
```
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17590 from HyukjinKwon/disable-dot-in-name.
## What changes were proposed in this pull request?
Fixed spelling of "charactor"
## How was this patch tested?
Spelling change only
Author: Brendan Dwyer <brendan.dwyer@ibm.com>
Closes#17611 from bdwyer2/SPARK-20298.
## What changes were proposed in this pull request?
Test failed because SPARK_HOME is not set before Spark is installed.
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17516 from felixcheung/rdircheckincran.
## What changes were proposed in this pull request?
Following up on #17483, add createTable (which is new in 2.2.0) and deprecate createExternalTable, plus a number of minor fixes
## How was this patch tested?
manual, unit tests
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17511 from felixcheung/rceatetable.
## What changes were proposed in this pull request?
Update doc to remove external for createTable, add refreshByPath in python
## How was this patch tested?
manual
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17512 from felixcheung/catalogdoc.
## What changes were proposed in this pull request?
minor update
zero323
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17526 from felixcheung/rfpgrowthfollowup.
## What changes were proposed in this pull request?
It seems cran check scripts corrects `R/pkg/DESCRIPTION` and follows the order in `Collate` fields.
This PR proposes to fix `catalog.R`'s order so that running this script does not show up a small diff in this file every time.
## How was this patch tested?
Manually via `./R/check-cran.sh`.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17528 from HyukjinKwon/minor-reorder-description.
## What changes were proposed in this pull request?
Adds SparkR API for FPGrowth: [SPARK-19825](https://issues.apache.org/jira/browse/SPARK-19825):
- `spark.fpGrowth` -model training.
- `freqItemsets` and `associationRules` methods with new corresponding generics.
- Scala helper: `org.apache.spark.ml.r. FPGrowthWrapper`
- unit tests.
## How was this patch tested?
Feature specific unit tests.
Author: zero323 <zero323@users.noreply.github.com>
Closes#17170 from zero323/SPARK-19825.
## What changes were proposed in this pull request?
Add a set of catalog API in R
```
"currentDatabase",
"listColumns",
"listDatabases",
"listFunctions",
"listTables",
"recoverPartitions",
"refreshByPath",
"refreshTable",
"setCurrentDatabase",
```
https://github.com/apache/spark/pull/17483/files#diff-6929e6c5e59017ff954e110df20ed7ff
## How was this patch tested?
manual tests, unit tests
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17483 from felixcheung/rcatalog.
JIRA Issue: https://issues.apache.org/jira/browse/SPARK-20123
## What changes were proposed in this pull request?
If $SPARK_HOME or $FWDIR variable contains spaces, then use "./dev/make-distribution.sh --name custom-spark --tgz -Psparkr -Phadoop-2.7 -Phive -Phive-thriftserver -Pmesos -Pyarn" build spark will failed.
## How was this patch tested?
manual tests
Author: zuotingbing <zuo.tingbing9@zte.com.cn>
Closes#17452 from zuotingbing/spark-bulid.
## What changes were proposed in this pull request?
It seems `checkType` and the type string in `structField` are not being tested closely. This string format currently seems SparkR-specific (see d1f6c64c4b/sql/core/src/main/scala/org/apache/spark/sql/api/r/SQLUtils.scala (L93-L131)) but resembles SQL type definition.
Therefore, it seems nicer if we test positive/negative cases in R side.
## How was this patch tested?
Unit tests in `test_sparkSQL.R`.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17439 from HyukjinKwon/r-typestring-tests.
## What changes were proposed in this pull request?
This PR proposes to match minor documentations changes in https://github.com/apache/spark/pull/17399 and https://github.com/apache/spark/pull/17380 to R/Python.
## How was this patch tested?
Manual tests in Python , Python tests via `./python/run-tests.py --module=pyspark-sql` and lint-checks for Python/R.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17429 from HyukjinKwon/minor-match-doc.
## What changes were proposed in this pull request?
SparkR ```spark.getSparkFiles``` fails when it was called on executors, see details at [SPARK-19925](https://issues.apache.org/jira/browse/SPARK-19925).
## How was this patch tested?
Add unit tests, and verify this fix at standalone and yarn cluster.
Author: Yanbo Liang <ybliang8@gmail.com>
Closes#17274 from yanboliang/spark-19925.
## What changes were proposed in this pull request?
When SparkR is installed as a R package there might not be any java runtime.
If it is not there SparkR's `sparkR.session()` will block waiting for the connection timeout, hanging the R IDE/shell, without any notification or message.
## How was this patch tested?
manually
- [x] need to test on Windows
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#16596 from felixcheung/rcheckjava.
## What changes were proposed in this pull request?
Update docs for NaN handling in approxQuantile.
## How was this patch tested?
existing tests.
Author: Zheng RuiFeng <ruifengz@foxmail.com>
Closes#17369 from zhengruifeng/doc_quantiles_nan.
## What changes were proposed in this pull request?
Currently JSON and CSV have exactly the same logic about handling bad records, this PR tries to abstract it and put it in a upper level to reduce code duplication.
The overall idea is, we make the JSON and CSV parser to throw a BadRecordException, then the upper level, FailureSafeParser, handles bad records according to the parse mode.
Behavior changes:
1. with PERMISSIVE mode, if the number of tokens doesn't match the schema, previously CSV parser will treat it as a legal record and parse as many tokens as possible. After this PR, we treat it as an illegal record, and put the raw record string in a special column, but we still parse as many tokens as possible.
2. all logging is removed as they are not very useful in practice.
## How was this patch tested?
existing tests
Author: Wenchen Fan <wenchen@databricks.com>
Author: hyukjinkwon <gurwls223@gmail.com>
Author: Wenchen Fan <cloud0fan@gmail.com>
Closes#17315 from cloud-fan/bad-record2.
## What changes were proposed in this pull request?
doc only change
## How was this patch tested?
manual
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17356 from felixcheung/rdfcheckpoint2.
## What changes were proposed in this pull request?
Add checkpoint, setCheckpointDir API to R
## How was this patch tested?
unit tests, manual tests
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17351 from felixcheung/rdfcheckpoint.
## What changes were proposed in this pull request?
This PR proposes to support an array of struct type in `to_json` as below:
```scala
import org.apache.spark.sql.functions._
val df = Seq(Tuple1(Tuple1(1) :: Nil)).toDF("a")
df.select(to_json($"a").as("json")).show()
```
```
+----------+
| json|
+----------+
|[{"_1":1}]|
+----------+
```
Currently, it throws an exception as below (a newline manually inserted for readability):
```
org.apache.spark.sql.AnalysisException: cannot resolve 'structtojson(`array`)' due to data type
mismatch: structtojson requires that the expression is a struct expression.;;
```
This allows the roundtrip with `from_json` as below:
```scala
import org.apache.spark.sql.functions._
import org.apache.spark.sql.types._
val schema = ArrayType(StructType(StructField("a", IntegerType) :: Nil))
val df = Seq("""[{"a":1}, {"a":2}]""").toDF("json").select(from_json($"json", schema).as("array"))
df.show()
// Read back.
df.select(to_json($"array").as("json")).show()
```
```
+----------+
| array|
+----------+
|[[1], [2]]|
+----------+
+-----------------+
| json|
+-----------------+
|[{"a":1},{"a":2}]|
+-----------------+
```
Also, this PR proposes to rename from `StructToJson` to `StructsToJson ` and `JsonToStruct` to `JsonToStructs`.
## How was this patch tested?
Unit tests in `JsonFunctionsSuite` and `JsonExpressionsSuite` for Scala, doctest for Python and test in `test_sparkSQL.R` for R.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17192 from HyukjinKwon/SPARK-19849.
## What changes were proposed in this pull request?
Passes R `tempdir()` (this is the R session temp dir, shared with other temp files/dirs) to JVM, set System.Property for derby home dir to move derby.log
## How was this patch tested?
Manually, unit tests
With this, these are relocated to under /tmp
```
# ls /tmp/RtmpG2M0cB/
derby.log
```
And they are removed automatically when the R session is ended.
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#16330 from felixcheung/rderby.
## What changes were proposed in this pull request?
It seems cran check scripts corrects `R/pkg/DESCRIPTION` and follows the order in `Collate` fields.
This PR proposes to fix this so that running this script does not show up a diff in this file.
## How was this patch tested?
Manually via `./R/check-cran.sh`.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17349 from HyukjinKwon/minor-cran.
## What changes were proposed in this pull request?
Add "experimental" API for SS in R
## How was this patch tested?
manual, unit tests
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#16982 from felixcheung/rss.
## What changes were proposed in this pull request?
Since we could not directly define the array type in R, this PR proposes to support array types in R as string types that are used in `structField` as below:
```R
jsonArr <- "[{\"name\":\"Bob\"}, {\"name\":\"Alice\"}]"
df <- as.DataFrame(list(list("people" = jsonArr)))
collect(select(df, alias(from_json(df$people, "array<struct<name:string>>"), "arrcol")))
```
prints
```R
arrcol
1 Bob, Alice
```
## How was this patch tested?
Unit tests in `test_sparkSQL.R`.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#17178 from HyukjinKwon/SPARK-19828.
## What changes were proposed in this pull request?
Port Tweedie GLM #16344 to SparkR
felixcheung yanboliang
## How was this patch tested?
new test in SparkR
Author: actuaryzhang <actuaryzhang10@gmail.com>
Closes#16729 from actuaryzhang/sparkRTweedie.
## What changes were proposed in this pull request?
RandomForest R Wrapper and GBT R Wrapper return param `maxDepth` to R models.
Below 4 R wrappers are changed:
* `RandomForestClassificationWrapper`
* `RandomForestRegressionWrapper`
* `GBTClassificationWrapper`
* `GBTRegressionWrapper`
## How was this patch tested?
Test manually on my local machine.
Author: Xin Ren <iamshrek@126.com>
Closes#17207 from keypointt/SPARK-19282.
### What changes were proposed in this pull request?
Observed by felixcheung in https://github.com/apache/spark/pull/16739, when users use the shuffle-enabled `repartition` API, they expect the partition they got should be the exact number they provided, even if they call shuffle-disabled `coalesce` later.
Currently, `CollapseRepartition` rule does not consider whether shuffle is enabled or not. Thus, we got the following unexpected result.
```Scala
val df = spark.range(0, 10000, 1, 5)
val df2 = df.repartition(10)
assert(df2.coalesce(13).rdd.getNumPartitions == 5)
assert(df2.coalesce(7).rdd.getNumPartitions == 5)
assert(df2.coalesce(3).rdd.getNumPartitions == 3)
```
This PR is to fix the issue. We preserve shuffle-enabled Repartition.
### How was this patch tested?
Added a test case
Author: Xiao Li <gatorsmile@gmail.com>
Closes#16933 from gatorsmile/CollapseRepartition.
## What changes were proposed in this pull request?
Added checks for name consistency of input data frames in union.
## How was this patch tested?
new test.
Author: actuaryzhang <actuaryzhang10@gmail.com>
Closes#17159 from actuaryzhang/sparkRUnion.
## What changes were proposed in this pull request?
Add column functions: to_json, from_json, and tests covering error cases.
## How was this patch tested?
unit tests, manual
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17134 from felixcheung/rtojson.
## What changes were proposed in this pull request?
Update R document to use JDK8.
## How was this patch tested?
manual tests
Author: Yuming Wang <wgyumg@gmail.com>
Closes#17162 from wangyum/SPARK-19550.
## What changes were proposed in this pull request?
Update doc for R, programming guide. Clarify default behavior for all languages.
## How was this patch tested?
manually
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#17128 from felixcheung/jsonwholefiledoc.
Update R doc:
1. columns, names and colnames returns a vector of strings, not **list** as in current doc.
2. `colnames<-` does allow the subset assignment, so the length of `value` can be less than the number of columns, e.g., `colnames(df)[1] <- "a"`.
felixcheung
Author: actuaryzhang <actuaryzhang10@gmail.com>
Closes#17115 from actuaryzhang/sparkRMinorDoc.
## What changes were proposed in this pull request?
Replace `iris` dataset with `Titanic` or other dataset in example and document.
## How was this patch tested?
Manual and existing test
Author: wm624@hotmail.com <wm624@hotmail.com>
Closes#17032 from wangmiao1981/example.
## What changes were proposed in this pull request?
The `[[` method is supposed to take a single index and return a column. This is different from base R which takes a vector index. We should check for this and issue warning or error when vector index is supplied (which is very likely given the behavior in base R).
Currently I'm issuing a warning message and just take the first element of the vector index. We could change this to an error it that's better.
## How was this patch tested?
new tests
Author: actuaryzhang <actuaryzhang10@gmail.com>
Closes#17017 from actuaryzhang/sparkRSubsetter.
## What changes were proposed in this pull request?
This is a follow-up PR of #16800
When doing SPARK-19456, we found that "" should be consider a NULL column name and should not be set. aggregationDepth should be exposed as an expert parameter.
## How was this patch tested?
Existing tests.
Author: wm624@hotmail.com <wm624@hotmail.com>
Closes#16945 from wangmiao1981/svc.
## What changes were proposed in this pull request?
We recently add the spark.svmLinear API for SparkR. We need to add an example and update the vignettes.
## How was this patch tested?
Manually run example.
Author: wm624@hotmail.com <wm624@hotmail.com>
Closes#16969 from wangmiao1981/example.
## What changes were proposed in this pull request?
SparkR ```approxQuantile``` supports input multiple columns.
## How was this patch tested?
Unit test.
Author: Yanbo Liang <ybliang8@gmail.com>
Closes#16951 from yanboliang/spark-19619.
## What changes were proposed in this pull request?
Add coalesce on DataFrame for down partitioning without shuffle and coalesce on Column
## How was this patch tested?
manual, unit tests
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#16739 from felixcheung/rcoalesce.
## What changes were proposed in this pull request?
Linear SVM classifier is newly added into ML and python API has been added. This JIRA is to add R side API.
Marked as WIP, as I am designing unit tests.
## How was this patch tested?
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: wm624@hotmail.com <wm624@hotmail.com>
Closes#16800 from wangmiao1981/svc.
## What changes were proposed in this pull request?
- this is cause by changes in SPARK-18444, SPARK-18643 that we no longer install Spark when `master = ""` (default), but also related to SPARK-18449 since the real `master` value is not known at the time the R code in `sparkR.session` is run. (`master` cannot default to "local" since it could be overridden by spark-submit commandline or spark config)
- as a result, while running SparkR as a package in IDE is working fine, CRAN check is not as it is launching it via non-interactive script
- fix is to add check to the beginning of each test and vignettes; the same would also work by changing `sparkR.session()` to `sparkR.session(master = "local")` in tests, but I think being more explicit is better.
## How was this patch tested?
Tested this by reverting version to 2.1, since it needs to download the release jar with matching version. But since there are changes in 2.2 (specifically around SparkR ML) that are incompatible with 2.1, some tests are failing in this config. Will need to port this to branch-2.1 and retest with 2.1 release jar.
manually as:
```
# modify DESCRIPTION to revert version to 2.1.0
SPARK_HOME=/usr/spark R CMD build pkg
# run cran check without SPARK_HOME
R CMD check --as-cran SparkR_2.1.0.tar.gz
```
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#16720 from felixcheung/rcranchecktest.
## What changes were proposed in this pull request?
Fix a bug in collect method for collecting timestamp column, the bug can be reproduced as shown in the following codes and outputs:
```
library(SparkR)
sparkR.session(master = "local")
df <- data.frame(col1 = c(0, 1, 2),
col2 = c(as.POSIXct("2017-01-01 00:00:01"), NA, as.POSIXct("2017-01-01 12:00:01")))
sdf1 <- createDataFrame(df)
print(dtypes(sdf1))
df1 <- collect(sdf1)
print(lapply(df1, class))
sdf2 <- filter(sdf1, "col1 > 0")
print(dtypes(sdf2))
df2 <- collect(sdf2)
print(lapply(df2, class))
```
As we can see from the printed output, the column type of col2 in df2 is converted to numeric unexpectedly, when NA exists at the top of the column.
This is caused by method `do.call(c, list)`, if we convert a list, i.e. `do.call(c, list(NA, as.POSIXct("2017-01-01 12:00:01"))`, the class of the result is numeric instead of POSIXct.
Therefore, we need to cast the data type of the vector explicitly.
## How was this patch tested?
The patch can be tested manually with the same code above.
Author: titicaca <fangzhou.yang@hotmail.com>
Closes#16689 from titicaca/sparkr-dev.
## What changes were proposed in this pull request?
After SPARK-19464, **SparkPullRequestBuilder** fails because it still tries to use hadoop2.3.
**BEFORE**
https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/72595/console
```
========================================================================
Building Spark
========================================================================
[error] Could not find hadoop2.3 in the list. Valid options are ['hadoop2.6', 'hadoop2.7']
Attempting to post to Github...
> Post successful.
```
**AFTER**
https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/72595/console
```
========================================================================
Building Spark
========================================================================
[info] Building Spark (w/Hive 1.2.1) using SBT with these arguments: -Phadoop-2.6 -Pmesos -Pkinesis-asl -Pyarn -Phive-thriftserver -Phive test:package streaming-kafka-0-8-assembly/assembly streaming-flume-assembly/assembly streaming-kinesis-asl-assembly/assembly
Using /usr/java/jdk1.8.0_60 as default JAVA_HOME.
Note, this will be overridden by -java-home if it is set.
```
## How was this patch tested?
Pass the existing test.
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#16858 from dongjoon-hyun/hotfix_run-tests.
## What changes were proposed in this pull request?
This pull request adds two new user facing functions:
- `to_date` which accepts an expression and a format and returns a date.
- `to_timestamp` which accepts an expression and a format and returns a timestamp.
For example, Given a date in format: `2016-21-05`. (YYYY-dd-MM)
### Date Function
*Previously*
```
to_date(unix_timestamp(lit("2016-21-05"), "yyyy-dd-MM").cast("timestamp"))
```
*Current*
```
to_date(lit("2016-21-05"), "yyyy-dd-MM")
```
### Timestamp Function
*Previously*
```
unix_timestamp(lit("2016-21-05"), "yyyy-dd-MM").cast("timestamp")
```
*Current*
```
to_timestamp(lit("2016-21-05"), "yyyy-dd-MM")
```
### Tasks
- [X] Add `to_date` to Scala Functions
- [x] Add `to_date` to Python Functions
- [x] Add `to_date` to SQL Functions
- [X] Add `to_timestamp` to Scala Functions
- [x] Add `to_timestamp` to Python Functions
- [x] Add `to_timestamp` to SQL Functions
- [x] Add function to R
## How was this patch tested?
- [x] Add Functions to `DateFunctionsSuite`
- Test new `ParseToTimestamp` Expression (*not necessary*)
- Test new `ParseToDate` Expression (*not necessary*)
- [x] Add test for R
- [x] Add test for Python in test.py
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: anabranch <wac.chambers@gmail.com>
Author: Bill Chambers <bill@databricks.com>
Author: anabranch <bill@databricks.com>
Closes#16138 from anabranch/SPARK-16609.
