HashMapVector

java.lang.Object
- ir.vsr.HashMapVector

```
public class HashMapVector
extends java.lang.Object
```
A data structure for a term vector for a document stored as a HashMap that maps tokens to Weight's that store the weight of that token in the document.
Needed as an efficient, indexed representation of sparse document vectors.

Field Summary

Fields
Modifier and Type Field and Description

java.util.Map<java.lang.String,Weight> hashMap
The HashMap that stores the mapping of tokens to Weights

Fields
Modifier and Type	Field and Description
`java.util.Map<java.lang.String,Weight>`	`hashMap` The HashMap that stores the mapping of tokens to Weights

Constructor Summary

Constructors
Constructor and Description

HashMapVector()

Constructors
Constructor and Description
`HashMapVector()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(HashMapVector vector)` Destructively add the given vector to the current vector
`void`	`addScaled(HashMapVector vector, double scalingFactor)` Destructively add a scaled version of the given vector to the current vector
`void`	`clear()` Clears the vector back to all zeros
`HashMapVector`	`copy()` Produce a copy of this HashMapVector with a new HashMap and new Weight's
`double`	`cosineTo(HashMapVector otherVector)` Computes cosine of angle to otherVector.
`double`	`cosineTo(HashMapVector otherVector, double length)` Computes cosine of angle to otherVector when also given otherVector's Euclidian length (Allows saving computation if length already known.
`java.util.Set<java.util.Map.Entry<java.lang.String,Weight>>`	`entrySet()` Returns the Set of MapEntries in the hashMap
`double`	`getWeight(java.lang.String token)` Return the weight of the given token in the vector
`double`	`increment(java.lang.String token)` Increment the weight for the given token in the vector by 1.
`double`	`increment(java.lang.String token, double amount)` Increment the weight for the given token in the vector by the given amount.
`double`	`increment(java.lang.String token, int amount)` Increment the weight for the given token in the vector by the given int
`double`	`length()` Compute Euclidian length (sqrt of sum of squares) of vector
`double`	`maxWeight()` Returns the maximum weight of any token in the vector.
`void`	`multiply(double factor)` Destructively multiply the vector by a constant
`void`	`print()` Print out the vector showing the tokens and their weights
`int`	`size()` Returns the number of tokens in the vector.
`void`	`subtract(HashMapVector vector)` Destructively subtract the given vector from the current vector
`java.lang.String`	`toString()` Return String of the vector showing the tokens and their weights

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

- Field Detail
  - hashMap
```
public java.util.Map<java.lang.String,Weight> hashMap
```
    The HashMap that stores the mapping of tokens to Weights
- Constructor Detail
  - HashMapVector
```
public HashMapVector()
```
- Method Detail
  - size
```
public int size()
```
    Returns the number of tokens in the vector.
  - clear
```
public void clear()
```
    Clears the vector back to all zeros
  - entrySet
```
public java.util.Set<java.util.Map.Entry<java.lang.String,Weight>> entrySet()
```
    Returns the Set of MapEntries in the hashMap
  - increment
```
public double increment(java.lang.String token,
               double amount)
```
    Increment the weight for the given token in the vector by the given amount.
  - getWeight
```
public double getWeight(java.lang.String token)
```
    Return the weight of the given token in the vector
  - increment
```
public double increment(java.lang.String token)
```
    Increment the weight for the given token in the vector by 1.
  - increment
```
public double increment(java.lang.String token,
               int amount)
```
    Increment the weight for the given token in the vector by the given int
  - add
```
public void add(HashMapVector vector)
```
    Destructively add the given vector to the current vector
  - addScaled
```
public void addScaled(HashMapVector vector,
             double scalingFactor)
```
    Destructively add a scaled version of the given vector to the current vector
  - subtract
```
public void subtract(HashMapVector vector)
```
    Destructively subtract the given vector from the current vector
  - multiply
```
public void multiply(double factor)
```
    Destructively multiply the vector by a constant
  - copy
```
public HashMapVector copy()
```
    Produce a copy of this HashMapVector with a new HashMap and new Weight's
  - maxWeight
```
public double maxWeight()
```
    Returns the maximum weight of any token in the vector.
  - print
```
public void print()
```
    Print out the vector showing the tokens and their weights
  - toString
```
public java.lang.String toString()
```
    Return String of the vector showing the tokens and their weights
    
    Overrides:
    
    toString in class java.lang.Object
  - cosineTo
```
public double cosineTo(HashMapVector otherVector)
```
    Computes cosine of angle to otherVector.
  - cosineTo
```
public double cosineTo(HashMapVector otherVector,
              double length)
```
    Computes cosine of angle to otherVector when also given otherVector's Euclidian length (Allows saving computation if length already known. more efficient when current vector is shorter than otherVector)
  - length
```
public double length()
```
    Compute Euclidian length (sqrt of sum of squares) of vector

Class HashMapVector

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

hashMap

Constructor Detail

HashMapVector

Method Detail

size

clear

entrySet

increment

getWeight

increment

increment

add

addScaled

subtract

multiply

copy

maxWeight

print

toString

cosineTo

cosineTo

length