Class Nysiis

Encodes a string into a NYSIIS value. NYSIIS is an encoding used to relate similar names, but can also be used as a general purpose scheme to find word with similar phonemes.

Inheritance

System.Object

Nysiis

Implements

IStringEncoder

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Lucene.Net.Analysis.Phonetic.Language

Assembly: Lucene.Net.Analysis.Phonetic.dll

Syntax

public class Nysiis : IStringEncoder

Remarks

NYSIIS features an accuracy increase of 2.7% over the traditional Soundex algorithm.

Algorithm description:

1. Transcode first characters of name
   1. MAC -> MCC
   2. KN -> NN
   3. K -> C
   4. PH -> FF
   5. PF -> FF
   6. SCH -> SSS
2. Transcode last characters of name
   1. EE, IE -> Y
   2. DT,RT,RD,NT,ND -> D
3. First character of key = first character of name
4. Transcode remaining characters by following these rules, incrementing by one character each time
   1. EV -> AF else A,E,I,O,U -> A
   2. Q -> G
   3. Z -> S
   4. M -> N
   5. KN -> N else K -> C
   6. SCH -> SSS
   7. PH -> FF
   8. H -> If previous or next is nonvowel, previous
   9. W -> If previous is vowel, previous
   10. Add current to key if current != last key character
5. If last character is S, remove it
6. If last characters are AY, replace with Y
7. If last character is A, remove it
8. Collapse all strings of repeated characters
9. Add original first character of name as first character of key

This class is immutable and thread-safe.

See: NYSIIS on Wikipedia

See: NYSIIS on dropby.com

since 1.7

Constructors

Nysiis()

Creates an instance of the Nysiis encoder with strict mode (original form), i.e. encoded strings have a maximum length of 6.

Declaration

public Nysiis()

Nysiis(Boolean)

Create an instance of the Nysiis encoder with the specified strict mode:

• true:encoded strings have a maximum length of 6
• false:encoded strings may have arbitrary length

Declaration

public Nysiis(bool strict)

Parameters

Type	Name	Description
System.Boolean	strict	The strict mode.

Properties

IsStrict

Indicates the strict mode for this Nysiis encoder. true if the encoder is configured for strict mode, false otherwise.

Declaration

public virtual bool IsStrict { get; }

Property Value

Type	Description
System.Boolean

Methods

Encode(String)

Encodes a string using the NYSIIS algorithm.

Declaration

public virtual string Encode(string str)

Parameters

Type	Name	Description
System.String	str	A string object to encode.

Returns

Type	Description
System.String	A Nysiis code corresponding to the string supplied.

Exceptions

Type	Condition
System.ArgumentException	If a character is not mapped.

GetNysiis(String)

Retrieves the NYSIIS code for a given string.

Declaration

public virtual string GetNysiis(string str)

Parameters

Type	Name	Description
System.String	str	String to encode using the NYSIIS algorithm.

Returns

Type	Description
System.String	A NYSIIS code for the string supplied.

Implements

IStringEncoder

See Also

Soundex