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author | Dongjoon Hyun <dongjoon@apache.org> | 2016-04-19 22:28:11 -0700 |
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committer | Davies Liu <davies.liu@gmail.com> | 2016-04-19 22:28:11 -0700 |
commit | 14869ae64eb27830179d4954a5dc3e0a1e1330b4 (patch) | |
tree | c294dde39b5d77c6086b3d08a726b1c8b401b95a /python/pyspark | |
parent | 6f1ec1f2670cd55bc852a810ca9d5c6a2651a9f2 (diff) | |
download | spark-14869ae64eb27830179d4954a5dc3e0a1e1330b4.tar.gz spark-14869ae64eb27830179d4954a5dc3e0a1e1330b4.tar.bz2 spark-14869ae64eb27830179d4954a5dc3e0a1e1330b4.zip |
[SPARK-14639] [PYTHON] [R] Add `bround` function in Python/R.
## What changes were proposed in this pull request?
This issue aims to expose Scala `bround` function in Python/R API.
`bround` function is implemented in SPARK-14614 by extending current `round` function.
We used the following semantics from Hive.
```java
public static double bround(double input, int scale) {
if (Double.isNaN(input) || Double.isInfinite(input)) {
return input;
}
return BigDecimal.valueOf(input).setScale(scale, RoundingMode.HALF_EVEN).doubleValue();
}
```
After this PR, `pyspark` and `sparkR` also support `bround` function.
**PySpark**
```python
>>> from pyspark.sql.functions import bround
>>> sqlContext.createDataFrame([(2.5,)], ['a']).select(bround('a', 0).alias('r')).collect()
[Row(r=2.0)]
```
**SparkR**
```r
> df = createDataFrame(sqlContext, data.frame(x = c(2.5, 3.5)))
> head(collect(select(df, bround(df$x, 0))))
bround(x, 0)
1 2
2 4
```
## How was this patch tested?
Pass the Jenkins tests (including new testcases).
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes #12509 from dongjoon-hyun/SPARK-14639.
Diffstat (limited to 'python/pyspark')
-rw-r--r-- | python/pyspark/sql/functions.py | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py index 5017ab5b36..dac842c0ce 100644 --- a/python/pyspark/sql/functions.py +++ b/python/pyspark/sql/functions.py @@ -467,16 +467,29 @@ def randn(seed=None): @since(1.5) def round(col, scale=0): """ - Round the value of `e` to `scale` decimal places if `scale` >= 0 + Round the given value to `scale` decimal places using HALF_UP rounding mode if `scale` >= 0 or at integral part when `scale` < 0. - >>> sqlContext.createDataFrame([(2.546,)], ['a']).select(round('a', 1).alias('r')).collect() - [Row(r=2.5)] + >>> sqlContext.createDataFrame([(2.5,)], ['a']).select(round('a', 0).alias('r')).collect() + [Row(r=3.0)] """ sc = SparkContext._active_spark_context return Column(sc._jvm.functions.round(_to_java_column(col), scale)) +@since(2.0) +def bround(col, scale=0): + """ + Round the given value to `scale` decimal places using HALF_EVEN rounding mode if `scale` >= 0 + or at integral part when `scale` < 0. + + >>> sqlContext.createDataFrame([(2.5,)], ['a']).select(bround('a', 0).alias('r')).collect() + [Row(r=2.0)] + """ + sc = SparkContext._active_spark_context + return Column(sc._jvm.functions.bround(_to_java_column(col), scale)) + + @since(1.5) def shiftLeft(col, numBits): """Shift the given value numBits left. |