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SOUNDEX

SOUNDEX

Encodes a string to facilitate searching

Category: Character

Syntax
Arguments
Details
Examples

Syntax

SOUNDEX(argument)

Arguments

argument
specifies any SAS character expression.

Details

The SOUNDEX function encodes a character string according to an algorithm originally developed by Margaret K. Odell and Robert C. Russel (US Patents 1261167 (1918) and 1435663 (1922)). The algorithm is described in Knuth, The Art of Computer Programming, Volume 3 (See References).

The SOUNDEX function returns a copy of the argument encoded by using the following steps.

  1. Retain the first letter in the argument and discard the following letters:

    A E H I O U W Y

  2. Assign the following numbers to these classes of letters:
    1: B F P V
    2: C G J K Q S X Z
    3: D T
    4: L
    5: M N
    6: R

  3. If two or more adjacent letters have the same classification from Step 2, discard all but the first. (Adjacent refers to the position in the word prior to discarding letters.)

The algorithm described in Knuth adds trailing zeroes and truncates the result to the length of 4. You can perform these operations with other SAS functions.

Examples

SAS Statements Results 

x=soundex('Paul');
put x;
 

 
P4
 

word='amnesty';
x=soundex(word);
put x;
 

 

A523


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