ImmutableSparseVector (LensKit Data Structures 2.0 API)

java.lang.Object
- org.grouplens.lenskit.vectors.SparseVector
- - org.grouplens.lenskit.vectors.ImmutableSparseVector

All Implemented Interfaces:

Serializable, Iterable<VectorEntry>
```
@Immutable
public final class ImmutableSparseVector
extends SparseVector
implements Serializable
```
Immutable sparse vectors. These vectors cannot be changed, even by other code, and are therefore safe to store and are thread-safe.
Use create(java.util.Map), SparseVector.empty(), immutable(), or MutableSparseVector.freeze() to create immutable sparse vectors.

Author:

GroupLens Research

See Also:
Serialized Form

Method Summary

Methods
Modifier and Type	Method and Description
`static ImmutableSparseVector`	`create(Map<Long,Double> data)` Construct a new immutable sparse vector from a map.
`<K> it.unimi.dsi.fastutil.longs.Long2ObjectMap<K>`	`getChannel(TypedSymbol<K> channelSymbol)` Fetch the channel stored under a particular typed symbol.
`Set<TypedSymbol<?>>`	`getChannelSymbols()` Retrieve all symbols that map to typed side channels for this vector.
`ImmutableSparseVector`	`getChannelVector(Symbol channelSymbol)` Get the vector associated with a particular unboxed channel.
`Set<Symbol>`	`getChannelVectorSymbols()` Retrieve all symbols that map to side channels for this vector.
`boolean`	`hasChannel(TypedSymbol<?> channelSymbol)` Return whether this sparse vector has a channel stored under a particular typed symbol.
`boolean`	`hasChannelVector(Symbol channelSymbol)` Return whether this sparse vector has a channel vector stored under a particular symbol.
`ImmutableSparseVector`	`immutable()` Return an immutable snapshot of this sparse vector.
`double`	`mean()` Compute and return the mean of the vector's values.
`MutableSparseVector`	`mutableCopy()` Return a mutable copy of this sparse vector.
`double`	`norm()` Compute and return the L2 norm (Euclidian length) of the vector.
`double`	`sum()` Compute and return the L1 norm (sum) of the vector.

Methods inherited from class org.grouplens.lenskit.vectors.SparseVector
containsKey, countCommonKeys, dot, empty, equals, fast, fast, fastIterator, fastIterator, get, get, get, hashCode, isEmpty, isSet, iterator, keyDomain, keysByValue, keysByValue, keySet, size, toString, unsetKeySet, values

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

- Method Detail
  - create
```
public static ImmutableSparseVector create(Map<Long,Double> data)
```
    Construct a new immutable sparse vector from a map.
    
    Parameters:
    data - The data. It may not contain any null values.
    
    Returns:
    An immutable sparse vector containing the specified data.
  - immutable
```
public ImmutableSparseVector immutable()
```
    Description copied from class: SparseVector
    
    Return an immutable snapshot of this sparse vector. The new vector's key domain will be equal to the SparseVector.keySet() of this vector.
    
    Specified by:
    
    immutable in class SparseVector
    
    Returns:
    An immutable sparse vector whose contents are the same as this vector. If the vector is already immutable, the returned object may be identical.
  - mutableCopy
```
public MutableSparseVector mutableCopy()
```
    Description copied from class: SparseVector
    
    Return a mutable copy of this sparse vector. The key domain of the mutable vector will be the same as this vector's key domain.
    
    Specified by:
    
    mutableCopy in class SparseVector
    
    Returns:
    A mutable sparse vector which can be modified without modifying this vector.
  - hasChannelVector
```
public boolean hasChannelVector(Symbol channelSymbol)
```
    Description copied from class: SparseVector
    
    Return whether this sparse vector has a channel vector stored under a particular symbol.
    
    Specified by:
    
    hasChannelVector in class SparseVector
    
    Parameters:
    channelSymbol - the symbol under which the channel was stored in the vector.
    
    Returns:
    whether this vector has such a channel right now.
  - hasChannel
```
public boolean hasChannel(TypedSymbol<?> channelSymbol)
```
    Description copied from class: SparseVector
    
    Return whether this sparse vector has a channel stored under a particular typed symbol.
    
    Specified by:
    
    hasChannel in class SparseVector
    
    Parameters:
    channelSymbol - the typed symbol under which the channel was stored in the vector.
    
    Returns:
    whether this vector has such a channel right now.
  - getChannelVector
```
public ImmutableSparseVector getChannelVector(Symbol channelSymbol)
```
    Description copied from class: SparseVector
    
    Get the vector associated with a particular unboxed channel.
    
    Specified by:
    
    getChannelVector in class SparseVector
    
    Parameters:
    channelSymbol - the symbol under which the channel was/is stored in the vector.
    
    Returns:
    The vector corresponding to the specified unboxed channel, or null if there is no such channel.
  - getChannel
```
public <K> it.unimi.dsi.fastutil.longs.Long2ObjectMap<K> getChannel(TypedSymbol<K> channelSymbol)
```
    Description copied from class: SparseVector
    
    Fetch the channel stored under a particular typed symbol.
    
    Specified by:
    
    getChannel in class SparseVector
    
    Parameters:
    channelSymbol - the typed symbol under which the channel was/is stored in the vector.
    
    Returns:
    the channel, which is itself a map from the key domain to objects of the channel's type, or null if there is no such channel.
  - getChannelVectorSymbols
```
public Set<Symbol> getChannelVectorSymbols()
```
    Description copied from class: SparseVector
    
    Retrieve all symbols that map to side channels for this vector.
    
    Specified by:
    
    getChannelVectorSymbols in class SparseVector
    
    Returns:
    A set of symbols, each of which identifies a side channel of the vector.
  - getChannelSymbols
```
public Set<TypedSymbol<?>> getChannelSymbols()
```
    Description copied from class: SparseVector
    
    Retrieve all symbols that map to typed side channels for this vector.
    
    Specified by:
    
    getChannelSymbols in class SparseVector
    
    Returns:
    A set of symbols, each of which identifies a side channel of the vector.
  - norm
```
public double norm()
```
    Description copied from class: SparseVector
    
    Compute and return the L2 norm (Euclidian length) of the vector.
    
    Overrides:
    
    norm in class SparseVector
    
    Returns:
    The L2 norm of the vector
  - sum
```
public double sum()
```
    Description copied from class: SparseVector
    
    Compute and return the L1 norm (sum) of the vector.
    
    Overrides:
    
    sum in class SparseVector
    
    Returns:
    the sum of the vector's values
  - mean
```
public double mean()
```
    Description copied from class: SparseVector
    
    Compute and return the mean of the vector's values.
    
    Overrides:
    
    mean in class SparseVector
    
    Returns:
    the mean of the vector

Class ImmutableSparseVector

Method Summary

Methods inherited from class org.grouplens.lenskit.vectors.SparseVector

Methods inherited from class java.lang.Object

Method Detail

create

immutable

mutableCopy

hasChannelVector

hasChannel

getChannelVector

getChannel

getChannelVectorSymbols

getChannelSymbols

norm

sum

mean