dim countOfChar( 255) ' all possible one-byte ASCII chars

    source$    ="1223334444"
    charCount  =len( source$)
    usedChar$  =""

    for i =1 to len( source$)   '   count which chars are used in source
        ch$             =mid$( source$, i, 1)
        if not( instr( usedChar$, ch$)) then usedChar$ =usedChar$ +ch$
        'currentCh$      =mid$(
        j               =instr( usedChar$, ch$)
        countOfChar( j) =countOfChar( j) +1
    next i

    l =len( usedChar$)
    for i =1 to l
        probability =countOfChar( i) /charCount
        entropy     =entropy -( probability *logBase( probability, 2))
    next i

    print " Characters used and the number of occurrences of each "
    for i =1 to l
        print " '"; mid$( usedChar$, i, 1); "'", countOfChar( i)
    next i

    print " Entropy of '"; source$; "' is  "; entropy; " bits."
    print " The result should be around 1.84644 bits."

    end
    function logBase( x, b) '   in LB log() is base 'e'.
        logBase =log( x) /log( 2)
    end function