Re: MIA, Ask an Expert: dice counts

[Seymour Papert <papert@xxxxxxxxxxxxx>]

 I am resending the following because it might seem mysterious to 
=anyone who has not followed the previous interchanges
about the problem.

What I wrote is addressed to someone I think called Damian who posed a 
problem that you will find at the bottom of this message.
-----------------

More comments on the dice roll problem that might give you something to 
think about:

Taken literally Susan's solution is a correct solution to a different  
problem than the one I thought you were posing. I thought you wanted 
the procedure  to tell you how many rolls actually happened up to the 
time a complete set was achieved.

But the great thing about programming is that this does not make her 
solution  "wrong."  Even if it does not quite do what (I think) you 
wanted, it still has a good idea in it,  which you can adapt  to solve 
the problem that  you wanted to solve.

But you have to add another idea as well: in some way you must  count 
the number of rolls that have been done up to the time the thing stops.

I won't deprive you of the fun of doing this yourself.

Seymour

P.S.
You might find it interesting to accompany me through the following 
thought steps that came after I wrote the above:

First thought:   I can't remember whether STOPALL exists in LogoWriter 
or whether it came in with MicroWorlds. If not  Damian would get into a 
bit of trouble. So0 I wondered how he could get out of it.
Second thought: Always ask: what would be the simplest way out of the 
trouble?
Third step: What would happen if he just removed  STOPALL from Susan's 
suggested procedure?
Fourth: Interesting guess---- even if STOPALL does exist in LogoWriter, 
the procedure it would print the same with or without the STOPALL 
.instruction.. but what would be happening inside the computer would be 
different !
(I don't have LogoWriter near where I am and so I haven't tried this 
/// I'm just guessing ..or thinking .. or whatever you call it.
I hope someone tries this and discusses what happened)

Worth pondering.

P.P.S. Since I have gone on about this longer than I meant to I think I 
should take the trouble to make quite clear how i interpreted Damian 
and Susan:

I read Susan as suggesting that Damian's diceroll procedure be changed 
to

to diceroll :n
prep
repeat :n [dice if (and :one > 0 :two > 0 :three > 0 :four > 0 :five > 0
:six > 0) [pr (se [After ] :n [ rolls I have a complete set] )] ]
end

to dice
make "roll random 6
if :roll = 0 [make "one :one + 1]
if :roll = 1 [make "two :two + 1]
if :roll = 2 [make "three :three + 1]
if :roll = 3 [make "four :four + 1]
if :roll = 4 [make "five :five + 1]
if :roll = 5 [make "six :six + 1]
end

to prep
make "one 0
make "two 0
make "three 0
make "four 0
make "five 0
make "six 0
end

Try it with a few inputs like diceroll 100, diceroll 50, diceroll 3 in 
two forms -- one as it stands, the other after removing the stopall.

Susan Einhorn wrote:
> This following solution works for LogoWirter and MicroWorlds.
>
> You could use the primitive "and". And reports true if ALL its inputs 
> are
> true (compare this to "or" which reports true if ANY of its inputs are
> true). Here's one idea:
>
> Add the instruction:
>
> If (and :one > 0 :two > 0 :three > 0 :four > 0 :five > 0 :six > 0) [pr 
> (se
> [After ] :n [ rolls I have a complete set] ) stopall]
>
> Add this inside the brackets of your repeat instruction.
>
> repeat :n [dice if (and :one > 0 :two > 0 :three > 0 :four > 0 :five > 
> 0
> :six > 0) [pr (se [After ] :n [ rolls I have a complete set] ) 
> stopall] ]
>
> That's somewhat difficult to read, so you could make it a subprocedure:
>
> To decide
> If (and :one > 0 :two > 0 :three > 0 :four > 0 :five > 0 :six > 0)
> [pr (se [After ] :n [ rolls I have a complete set] ) stopall]
> end
>
> Then your repeat line will be more readable:
>
> repeat :n [dice decide]
>
> Note, this stops all the procedures.  You didn't say if this is what 
> you
> wanted to do, but, if not, there are ways to keep the dice rolling.
>
> Susan
>
>
>  -----Original Message-----
> From: 	mwforum-admin@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
> [mailto:mwforum-admin@xxxxxxxxxxxxxxxxxxxxxxxxxxxx]  On Behalf Of Ask 
> an
> Expert - Question
> Sent:	Thursday, May 18, 2006 10:27 AM
> To:	mwforum@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Subject:	[MWForum] MIA, Ask an Expert: dice counts
>
> This is an automatic message sent from the web form at:
> http://mia.openworldlearning.org/mwforum.htm
>
> from: Damian <dnicetin@xxxxxxxxxxxx>
> date: Thu May 18 01:03:37 2006
>
> Hello
>
> I have a question.. I have written the following program to simulate 
> the
> results from a dice roll and it works fine..
>
> to dice
> make "roll random 6
> if :roll = 0 [make "one :one + 1]
> if :roll = 1 [make "two :two + 1]
> if :roll = 2 [make "three :three + 1]
> if :roll = 3 [make "four :four + 1]
> if :roll = 4 [make "five :five + 1]
> if :roll = 5 [make "six :six + 1]
> end
>
> to diceroll :n
> make "one 0 make "two 0 make "three 0 make "four 0 make "five 0 make 
> "six 0
> repeat :n [dice]
> print "one print :one
> print "two print :two
> print "three print :three
> print "four print :four
> print "five print :five
> print "six print :six
> end
>
> My problem is, that I want to change this procedure so that it counts 
> the
> number of rolls that it takes before I get the values 1, 2, 3, 4, 5 
> and 6
> (i.e a complete set of numbers, but not necessarily in numerical order)
>
> HELP!!!, Im stuck. are there any Logowriter Guru's out there that can 
> help?
>
>
>
>
>
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