Re: Evaluation of boolean functions in Mathematica 8
- To: mathgroup at smc.vnet.net
- Subject: [mg127577] Re: Evaluation of boolean functions in Mathematica 8
- From: Bob Hanlon <hanlonr357 at gmail.com>
- Date: Sat, 4 Aug 2012 21:48:55 -0400 (EDT)
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Re your side note, use FullForm Clear[truthTable] truthTable[equ_, form_: TraditionalForm] := Module[{v = Flatten[ {Union[BooleanVariables[equ]], equ}]}, Grid[Join[ {Style[form[#], Bold] & /@ v}, BooleanTable[v]], Frame -> All, FrameStyle -> LightGray]] equ = Riffle @@ (# @@@ Subsets[{p, q, r}, {2, 3}] & /@ {Or, And}); abbrev = {True -> Style["T", Blue, Bold], False -> Style["F", Gray]}; truthTable[equ] /. abbrev truthTable[equ, StandardForm] /. abbrev truthTable[equ, FullForm] /. abbrev Change default form to taste. Bob Hanlon On Sat, Aug 4, 2012 at 5:59 AM, Dana DeLouis <dana2010 at me.com> wrote: >> g[True,True,True] >> But the above statement does not evaluate g at the data-point given,... > > Hi. Just some additional ideas. Here's what you have: > > equ=And[p,q,r] > > f=BooleanConvert[equ,"BFF"] > BooleanFunction[<3>][p,q,r] > > Notice that the equation has p,q,r assigned to it. > Therefore, just assign a value to the variables. > > f//FullForm > BooleanFunction[Rule["BDD",List[3,0,2,-1,1,3,-1,2,1,-1]]][p,q,r] > > f/.{p->True,q->True,r->False} > False > > > Slightly better might be: > > BooleanTable[f,{p,q,r}] > {True,False,False,False,False,False,False,False} > > > As a side note, notice that using x,y,z will not work as the function is expecting p,q,r. > > BooleanTable[f,{x,y,z}] > < does not work > > > > Using your equation, we see that there is only 1 output with True, and the rest are False. > What generated the True condition? All False, All True, or something in-between? > Here's a general idea you may find interesting. > I've includes "steps" so as to see intermediate steps one may want to look at leading up to the final solution. > > > TruthTable[equ_,steps_List:{}]:=Module[{v}, > v = BooleanVariables[equ]; > AppendTo[v,{steps,equ}]; > v=Flatten[v]; > > MatrixForm[BooleanTable[v], > TableHeadings->{Automatic,v}] > ] > > > Here's your example. It appears the output is true when all inputs are true. > (I know... this example was easy) > > > TruthTable[equ] > ( p q r p&&q&&r > 1 True True True True > 2 True True False False > 3 True False True False > 4 True False False False > 5 False True True False > 6 False True False False > 7 False False True False > 8 False False False False > ) > > > This example is also easy, but suppose one didn't know the intermediate steps. > If one didn't know what the final NOT did, you could look at the inside part prior to the final NOT. > > > equ=Not[Or[And[x,y],z]]; > > // additional things one may want to look at: > > steps = {And[x,y], Or[And[x,y],z]}; > > TruthTable[equ,steps] > ( x y z x&&y (x&&y)||z !((x&&y)||z) > 1 True True True True True False > 2 True True False True True False > > etc... > ) > > > As a side note, does anyone know of a simple way to keep the input equation as And[p,q,r] ? > > This gets simplified to p&&q&&r. > I've been trying to find a way (without typing it as string) to keep the original version of And[p,q,r] in the heading row. > ~Thanks. > > > = = = = = = = = = = > HTH :>) > Dana DeLouis > Mac & Math 8 > = = = = = = = = = = > > > > On Aug 1, 4:57 am, lalwani.ak... at gmail.com wrote: >> Hello, >> >> I want to evaluate a Boolean function by substituting True and False values for its variables, to get a True or False value at the output. Example, >> >> g = BooleanConvert[And[p, q, r], "BFF"] >> >> g[True,True,True] >> >> But the above statement does not evaluate g at the data-point given, but instead returns the statement, >> >> BooleanFunction[<3>][p,q,r][True,True,True] >> >> Can anybody please suggest how to proceed? >> >> Thanks a lot.
- References:
- Re: Evaluation of boolean functions in Mathematica 8
- From: Dana DeLouis <dana2010@me.com>
- Re: Evaluation of boolean functions in Mathematica 8