#TESTSTR="1223334444"
NewMap uchar.i() : Define.d e

Procedure.d nlog2(x.d) : ProcedureReturn Log(x)/Log(2) : EndProcedure

Procedure countchar(s$, Map uchar())
  If Len(s$)
    uchar(Left(s$,1))=CountString(s$,Left(s$,1))
    s$=RemoveString(s$,Left(s$,1))
    ProcedureReturn countchar(s$, uchar())
  EndIf
EndProcedure

countchar(#TESTSTR,uchar())

ForEach uchar()
  e-uchar()/Len(#TESTSTR)*nlog2(uchar()/Len(#TESTSTR))
Next

OpenConsole()
Print("Entropy of ["+#TESTSTR+"] = "+StrD(e,15))
Input()