Min (Apache Beam SDK 0.2.0-incubating API)

java.lang.Object
- org.apache.beam.sdk.transforms.Min

```
public class Min
extends Object
```
PTransforms for computing the minimum of the elements in a PCollection, or the minimum of the values associated with each key in a PCollection of KVs.
Example 1: get the minimum of a PCollection of Doubles.
```
 
 PCollection<Double> input = ...;
 PCollection<Double> min = input.apply(Min.doublesGlobally());
  
```
Example 2: calculate the minimum of the Integers associated with each unique key (which is of type String).
```
 
 PCollection<KV<String, Integer>> input = ...;
 PCollection<KV<String, Integer>> minPerKey = input
     .apply(Min.<String>integersPerKey());
  
```

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Min.MinDoubleFn` A `CombineFn` that computes the minimum of a collection of `Double`s, useful as an argument to `Combine.globally(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)` or `Combine.perKey(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)`.
`static class`	`Min.MinFn<T>` A `CombineFn` that computes the maximum of a collection of elements of type `T` using an arbitrary `Comparator`, useful as an argument to `Combine.globally(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)` or `Combine.perKey(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)`.
`static class`	`Min.MinIntegerFn` A `CombineFn` that computes the minimum of a collection of `Integer`s, useful as an argument to `Combine.globally(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)` or `Combine.perKey(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)`.
`static class`	`Min.MinLongFn` A `CombineFn` that computes the minimum of a collection of `Long`s, useful as an argument to `Combine.globally(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)` or `Combine.perKey(org.apache.beam.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>)`.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static Combine.Globally<Double,Double>`	`doublesGlobally()` Returns a `PTransform` that takes an input `PCollection<Double>` and returns a `PCollection<Double>` whose contents is the minimum of the input `PCollection`'s elements, or `Double.POSITIVE_INFINITY` if there are no elements.
`static <K> Combine.PerKey<K,Double,Double>`	`doublesPerKey()` Returns a `PTransform` that takes an input `PCollection<KV<K, Double>>` and returns a `PCollection<KV<K, Double>>` that contains an output element mapping each distinct key in the input `PCollection` to the minimum of the values associated with that key in the input `PCollection`.
`static <T extends Comparable<? super T>> Combine.Globally<T,T>`	`globally()` Returns a `PTransform` that takes an input `PCollection<T>` and returns a `PCollection<T>` whose contents is the minimum according to the natural ordering of `T` of the input `PCollection`'s elements, or `null` if there are no elements.
`static <T,ComparatorT extends Comparator<? super T> & Serializable> Combine.Globally<T,T>`	`globally(ComparatorT comparator)` Returns a `PTransform` that takes an input `PCollection<T>` and returns a `PCollection<T>` whose contents is the minimum of the input `PCollection`'s elements, or `null` if there are no elements.
`static Combine.Globally<Integer,Integer>`	`integersGlobally()` Returns a `PTransform` that takes an input `PCollection<Integer>` and returns a `PCollection<Integer>` whose contents is a single value that is the minimum of the input `PCollection`'s elements, or `Integer.MAX_VALUE` if there are no elements.
`static <K> Combine.PerKey<K,Integer,Integer>`	`integersPerKey()` Returns a `PTransform` that takes an input `PCollection<KV<K, Integer>>` and returns a `PCollection<KV<K, Integer>>` that contains an output element mapping each distinct key in the input `PCollection` to the minimum of the values associated with that key in the input `PCollection`.
`static Combine.Globally<Long,Long>`	`longsGlobally()` Returns a `PTransform` that takes an input `PCollection<Long>` and returns a `PCollection<Long>` whose contents is the minimum of the input `PCollection`'s elements, or `Long.MAX_VALUE` if there are no elements.
`static <K> Combine.PerKey<K,Long,Long>`	`longsPerKey()` Returns a `PTransform` that takes an input `PCollection<KV<K, Long>>` and returns a `PCollection<KV<K, Long>>` that contains an output element mapping each distinct key in the input `PCollection` to the minimum of the values associated with that key in the input `PCollection`.
`static <K,T extends Comparable<? super T>> Combine.PerKey<K,T,T>`	`perKey()` Returns a `PTransform` that takes an input `PCollection<KV<K, T>>` and returns a `PCollection<KV<K, T>>` that contains an output element mapping each distinct key in the input `PCollection` to the minimum according to the natural ordering of `T` of the values associated with that key in the input `PCollection`.
`static <K,T,ComparatorT extends Comparator<? super T> & Serializable> Combine.PerKey<K,T,T>`	`perKey(ComparatorT comparator)` Returns a `PTransform` that takes an input `PCollection<KV<K, T>>` and returns a `PCollection<KV<K, T>>` that contains one output element per key mapping each to the minimum of the values associated with that key in the input `PCollection`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - integersGlobally
```
public static Combine.Globally<Integer,Integer> integersGlobally()
```
    Returns a PTransform that takes an input PCollection<Integer> and returns a PCollection<Integer> whose contents is a single value that is the minimum of the input PCollection's elements, or Integer.MAX_VALUE if there are no elements.
  - integersPerKey
```
public static <K> Combine.PerKey<K,Integer,Integer> integersPerKey()
```
    Returns a PTransform that takes an input PCollection<KV<K, Integer>> and returns a PCollection<KV<K, Integer>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.
    See Combine.PerKey for how this affects timestamps and windowing.
  - longsGlobally
```
public static Combine.Globally<Long,Long> longsGlobally()
```
    Returns a PTransform that takes an input PCollection<Long> and returns a PCollection<Long> whose contents is the minimum of the input PCollection's elements, or Long.MAX_VALUE if there are no elements.
  - longsPerKey
```
public static <K> Combine.PerKey<K,Long,Long> longsPerKey()
```
    Returns a PTransform that takes an input PCollection<KV<K, Long>> and returns a PCollection<KV<K, Long>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.
    See Combine.PerKey for how this affects timestamps and windowing.
  - doublesGlobally
```
public static Combine.Globally<Double,Double> doublesGlobally()
```
    Returns a PTransform that takes an input PCollection<Double> and returns a PCollection<Double> whose contents is the minimum of the input PCollection's elements, or Double.POSITIVE_INFINITY if there are no elements.
  - doublesPerKey
```
public static <K> Combine.PerKey<K,Double,Double> doublesPerKey()
```
    Returns a PTransform that takes an input PCollection<KV<K, Double>> and returns a PCollection<KV<K, Double>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.
    See Combine.PerKey for how this affects timestamps and windowing.
  - globally
```
public static <T extends Comparable<? super T>> Combine.Globally<T,T> globally()
```
    Returns a PTransform that takes an input PCollection<T> and returns a PCollection<T> whose contents is the minimum according to the natural ordering of T of the input PCollection's elements, or null if there are no elements.
  - perKey
```
public static <K,T extends Comparable<? super T>> Combine.PerKey<K,T,T> perKey()
```
    Returns a PTransform that takes an input PCollection<KV<K, T>> and returns a PCollection<KV<K, T>> that contains an output element mapping each distinct key in the input PCollection to the minimum according to the natural ordering of T of the values associated with that key in the input PCollection.
    See Combine.PerKey for how this affects timestamps and windowing.
  - globally
```
public static <T,ComparatorT extends Comparator<? super T> & Serializable> Combine.Globally<T,T> globally(ComparatorT comparator)
```
    Returns a PTransform that takes an input PCollection<T> and returns a PCollection<T> whose contents is the minimum of the input PCollection's elements, or null if there are no elements.
  - perKey
```
public static <K,T,ComparatorT extends Comparator<? super T> & Serializable> Combine.PerKey<K,T,T> perKey(ComparatorT comparator)
```
    Returns a PTransform that takes an input PCollection<KV<K, T>> and returns a PCollection<KV<K, T>> that contains one output element per key mapping each to the minimum of the values associated with that key in the input PCollection.
    See Combine.PerKey for how this affects timestamps and windowing.

Class Min

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

integersGlobally

integersPerKey

longsGlobally

longsPerKey

doublesGlobally

doublesPerKey

globally

perKey

globally

perKey