org.apache.ignite.ml.util

Class Utils

java.lang.Object

org.apache.ignite.ml.util.Utils

public class Utils
extends Object

Class with various utility methods.

Constructor Summary

Constructors

Constructor and Description
Utils()

Method Summary

Modifier and Type	Method and Description
static <T> Stream<T>	asStream(Iterator<T> iter) Convert given iterator to a stream.
static <T> Stream<T>	asStream(Iterator<T> iter, long cnt) Convert given iterator to a stream with known count of entries.
static <T> T	copy(T orig) Perform deep copy of an object.
static <T extends Serializable> T	deserialize(byte[] o) Deserialized object represented as a byte array.
static int[]	selectKDistinct(int n, int k) Select k distinct integers from range [0, n) with reservoir sampling: https://en.wikipedia.org/wiki/Reservoir_sampling.
static int[]	selectKDistinct(int n, int k, Random rand) Select k distinct integers from range [0, n) with reservoir sampling: https://en.wikipedia.org/wiki/Reservoir_sampling.
static <T extends Serializable> byte[]	serialize(T o) Serialized the specified object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Utils

public Utils()

Method Detail

copy

public static <T> T copy(T orig)

Perform deep copy of an object.

Type Parameters:

T - Class of original object;

Parameters:

orig - Original object.

Returns:

Deep copy of original object.

selectKDistinct

public static int[] selectKDistinct(int n,
                                    int k,
                                    Random rand)

Select k distinct integers from range [0, n) with reservoir sampling: https://en.wikipedia.org/wiki/Reservoir_sampling.

Parameters:

n - Number specifying left end of range of integers to pick values from.

k - Count specifying how many integers should be picked.

rand - RNG.

Returns:

Array containing k distinct integers from range [0, n);

selectKDistinct

public static int[] selectKDistinct(int n,
                                    int k)

Select k distinct integers from range [0, n) with reservoir sampling: https://en.wikipedia.org/wiki/Reservoir_sampling. Equivalent to selectKDistinct(n, k, new Random()).

Parameters:

n - Number specifying left end of range of integers to pick values from.

k - Count specifying how many integers should be picked.

Returns:

Array containing k distinct integers from range [0, n);

asStream

public static <T> Stream<T> asStream(Iterator<T> iter,
                                     long cnt)

Convert given iterator to a stream with known count of entries.

Type Parameters:

T - Type of entries.

Parameters:

iter - Iterator.

cnt - Count.

Returns:

Stream constructed from iterator.

asStream

public static <T> Stream<T> asStream(Iterator<T> iter)

Convert given iterator to a stream.

Type Parameters:

T - Iterator content type.

Parameters:

iter - Iterator.

Returns:

Stream constructed from iterator.

serialize

public static <T extends Serializable> byte[] serialize(T o)

Serialized the specified object.

Parameters:

o - Object to be serialized.

Returns:

Serialized object as byte array.

deserialize

public static <T extends Serializable> T deserialize(byte[] o)

Deserialized object represented as a byte array.

Type Parameters:

T - Type of serialized object.

Parameters:

o - Serialized object.

Returns:

Deserialized object.