RANDWORD

Generate a random word from an alphabet

Description

RANDWORD generates a random word from an alphabet. The words are selected from the lexicographically ordered list of all words of the given length using a random index generated with 'rand'.

    WORD = RANDWORD(alpha, wordSize) returns a random word in
    the alphabet 'alpha', with the number of symbols 'wordSize'.
    The result WORD has size 1 x wordSize.

    WORD = RANDWORD(alpha, wordSize, numWords) returns
    'numWords' random words in the alphabet 'alpha', with the
     number of symbols 'wordSize'. The result WORD has size
     numWords x wordSize.

    Example:
    Generate 4 words of length 5 from the alphabet 'A', 'B', ..., 'Z'
       word = randword('A':'Z', 5, 4)
       word =
       VPQQT
       PFQPQ
       OHPYM
       XWAPM

    The method of randword is to select a random word from the
    lexicographically sorted list of all words on alpha of length
    wordSize. With n = length(alpha) and w = wordSize, the steps
    are
       1) Get a random number r on the interval 1:n^w.
       2) Compute base n expansion of r.
       3) Make word with symbols of 'alpha' indexed by
           base n digits of r.

   Author: Tom Richardson
           trichardson AT xrite DOT com
   Date: 14 July 2009
       
   Changed the routine to use multiple passes to ensure that values of
   lexIndex stay below 2^31 - 1, thus avoiding roundoff error in
   alphaSize.
   Modified: Tom Richardson
   Date: 21 January 2010

• MATLAB release: MATLAB 7.9 (2009b)

[Jos (10584)]

How is this different from the more simple approach:

idx = ceil(numel(alpha)*rand(n,w)) ;
words = alpha(idx)?

Note that the variable "word" is growing inside the lloop, making this algorithm potentially very slow.

A final and positive comment: the help is quite adequate with a description of the in- and outputs, the algorithm and an example. A "See Also" line, referencing RAND and RANDSAMPLE would improve it even further.