;---------------------------------------------------
	; Copyright Karl-Uwe Frank
	;
	; I place this source code into Public Domain
	;
	
	
	;---------------------------------------------------
	; http://rosettacode.org/wiki/Entropy#PureBasic
	;
	Define.d e
	 
	Procedure.d nlog2(x.d) : ProcedureReturn Log(x)/Log(2) : EndProcedure
	
	
	Procedure CollectEntropy()
		Define i.u, sourcelen.u 
	  Define nHexVal.b
	  
	  ; source = "1223334444" // Debug
	  ; source = "5dc6c6487d" // Debug
	  sourcelen = mb.size-1
	  Dim inDataPtr As Ptr = mb
	  
	  'Print "sourcelen = " + str(sourcelen) // Debug
	  
	  For i = 0 To sourcelen
	    nHexVal = inDataPtr.byte(i)
	    totalchar(nHexVal) = totalchar(nHexVal) + 1
	  Next i
	EndProcedure
	
	
	
	Procedure CalcualteEntropy()
		Define i.u
		Define probability.d 
		
		For i = 0 To 255
			; If no bytes of this value were seen in the value, it doesn't affect
			; the entropy of the file.
			If totalchar(i) > 0 Then
				; Calculate the probability of seeing this byte in the file, As a floating-point number
				probability = totalchar(i) / inFileSize
				EntropyResult = EntropyResult - (probability * Log(probability) / Log(base))
			EndIf
		Next i
  EndProcedure
	
  
  
	OpenConsole()
	
	;---------------------------------------------------
	; Compare the entropy of this hex string
	;
	FreeMap(uchar())
	NewMap uchar.i()
	e = 0
	countchar(key_hex, uchar())
	
	ForEach uchar()  
	  e-uchar()/Len(key_hex)*nlog2(uchar()/Len(key_hex))  
	Next
	
	Define.s info_hex
	
	For i = 0 To (Len(key)/2)-2
		info_hex + Mid(key, (i*2)+1, 2) +":"
	Next
	
	info_hex + Mid(key, (i*2)+1, 2)
	
	PrintN("")
	PrintN("Hex String to check:  "+ info_hex)
	PrintN("----------------------------------------------------------")
	PrintN("Entropy = "+StrD(e,15))
	PrintN("")	
	
	CloseConsole()
	
	End 0