RANDWORD

Generate a random word from an alphabet

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