anyone good with doing math on excel?

phrontister · 2012-04-27 06:00:24

Oh, and please omit the "Mr". That makes me feel like I'm my dad!

phrontister · 2012-04-27 06:01:41

Hi Bobby,

Yes, I had fun with that. I didn't know the iteration trick until the dice roll problem, but the thought sprang up in my mind and I came up with the trigger idea (B2*0 in cell B2) to utilize circular referencing. No doubt there's a proper way to do that, but mine worked and I haven't looked further.

The mathematics way I haven't got the first clue about...but, as you say, I'm sure it's a little nasty.

Raito · 2012-04-27 06:02:01

I am sorry,phrontister

bobbym · 2012-04-27 06:03:39

Hi phrontister;

Good to see you. Your a clever guy even if you aren't a little person.

phrontister · 2012-04-27 06:12:04

Hi Bobby,

Sorry to deflate your balloon (which all little people possess), but little people aren't at all clever. Wrong forum for this clue, I know...I'll copy it over to the right one.
Can't continue with that puzzle tonight, though, cos it's actually this morning...well, what's left of it!

bobbym · 2012-04-27 06:14:05

I know they are also doomed. Have a pleasant night.

phrontister · 2012-04-27 06:14:27

Oh...I can't do that! "Topic closed". What now?

bobbym · 2012-04-27 06:16:02

Sorry, it is closed pending MIF's review of it. I can do nothing right now about that. Please hold on to the clue and post tomorrow.

phrontister · 2012-04-27 06:16:50

Ok. G'night.

bobbym · 2012-04-27 06:17:34

Okay, see you later.

phrontister · 2012-04-28 00:38:23

In my posts #14 & #17 I've now included animated gifs of calculation results so you can see the effect of the iterations.

I increased column B's font size for a more vivid display...which slowed down the animations significantly.

Last edited by phrontister (2017-02-26 00:17:51)

phrontister · 2013-05-02 21:17:41

Hi Bobby,

Re the coin-flipping puzzle mentioned in post #17, could you please help me with my M code? I've done two versions of it, and version A works but version B's got a snag I haven't been able to fix.

Version A:

c = 0;
For[i = 0, i < 10000, i++,
 If[StringCount[ToString[FromDigits[RandomInteger[1, 10]]], "1111"] > 0, c = c + 1]]; N[c/i*100 "%"]

Version B:

N[Total[StringCount[Table[ToString[FromDigits[RandomInteger[1, 10]]], {10000}], "1111"]]/10000*100 "%"]

The problem with version B is that it counts multiple occurrences of "1111" in an element: eg, "1111011110" scores 2 wins instead of 1, which incorrectly inflates the result.

Also, is there a function (something like StringCount) that can test the RandomInteger lists to see if they contain four consecutive elements that are all "1", so that I can eliminate "[ToString[FromDigits"? StringCount only works on strings (I think), and the only way I could get it to look at RandomInteger's lists was to convert the lists to numbers with FromDigits and then to strings with ToString...which seems to be two steps too many. But I couldn't find anything better (briefer).

Version A takes about 50% longer than version B.

Last edited by phrontister (2013-05-02 21:19:11)

bobbym · 2013-05-02 21:26:07

This problem is also in another thread. I have not gone into it because the OP over there is not ready for a better idea. You unfortunately are.

phrontister · 2013-05-02 21:28:41

Yes, I saw that thread and I agree with you, which is why I posted here.

Last edited by phrontister (2013-05-02 21:30:01)

bobbym · 2013-05-02 21:43:07

Are you attempting to solve this with a simulation?

anonimnystefy · 2013-05-02 22:02:59

Have you tried using

If[StringFreeQ[...,"1111"],0,1]

bobbym · 2013-05-02 22:08:47

The right way is not to simulate but to enumerate. I am getting 251 / 1024. The stupidity of the question is monumental! Why would they want to do a simulation of 10000 trials when there are only 1024 possibilities?

Try this:

s = Tuples[{0, 1}, 10];
(Cases[s, {___, 1, 1, 1, 1, ___}] // Length)/1024

B) Can be adjusted like this,

(Select[StringCount[
     Table[ToString[FromDigits[RandomInteger[1, 10]]], {10000}], 
     "1111"], # > 0 &] // Length)/10000.

anonimnystefy · 2013-05-02 22:50:03

Instead of Cases[...]//Length you can just use Count[...].

bobbym · 2013-05-02 22:57:42

Hi;

Yes, you can. the important thing is the difference in the method of solution. The enumeration gives the exact answer, something the simulation can never give.

anonimnystefy · 2013-05-02 23:00:51

Yes, but if we wanted a simulation, phro's way is a good way to go.

bobbym · 2013-05-02 23:04:07

Not exactly, string operations are not necessary. It is more convenient to work with the preferred container of M. Lists!

anonimnystefy · 2013-05-02 23:06:05

I meant, in the sense of idea, bot in te sense of implementation.

bobbym · 2013-05-02 23:12:50

The first bit of code does run a good simulation.

anonimnystefy · 2013-05-02 23:35:45

Here is my own code with no strings:

Count[Table[RandomInteger[], {10000}, {10}], {___, 1, 1, 1, 1, ___}]/10000 // N

Last edited by anonimnystefy (2013-05-02 23:37:32)

bobbym · 2013-05-02 23:45:23

You will find this to be faster:

Count[Table[
  RandomVariate[DiscreteUniformDistribution[{0, 1}], 
   10], {10000}], {___, 1, 1, 1, 1, ___}]

Math Is Fun Forum

#26 2012-04-27 06:00:24

Re: anyone good with doing math on excel?

#27 2012-04-27 06:01:41

Re: anyone good with doing math on excel?

#28 2012-04-27 06:02:01

Re: anyone good with doing math on excel?

#29 2012-04-27 06:03:39

Re: anyone good with doing math on excel?

#30 2012-04-27 06:12:04

Re: anyone good with doing math on excel?

#31 2012-04-27 06:14:05

Re: anyone good with doing math on excel?

#32 2012-04-27 06:14:27

Re: anyone good with doing math on excel?

#33 2012-04-27 06:16:02

Re: anyone good with doing math on excel?

#34 2012-04-27 06:16:50

Re: anyone good with doing math on excel?

#35 2012-04-27 06:17:34

Re: anyone good with doing math on excel?

#36 2012-04-28 00:38:23

Re: anyone good with doing math on excel?

#37 2013-05-02 21:17:41

Re: anyone good with doing math on excel?

#38 2013-05-02 21:26:07

Re: anyone good with doing math on excel?

#39 2013-05-02 21:28:41

Re: anyone good with doing math on excel?

#40 2013-05-02 21:43:07

Re: anyone good with doing math on excel?

#41 2013-05-02 22:02:59

Re: anyone good with doing math on excel?

#42 2013-05-02 22:08:47

Re: anyone good with doing math on excel?

#43 2013-05-02 22:50:03

Re: anyone good with doing math on excel?

#44 2013-05-02 22:57:42

Re: anyone good with doing math on excel?

#45 2013-05-02 23:00:51

Re: anyone good with doing math on excel?

#46 2013-05-02 23:04:07

Re: anyone good with doing math on excel?

#47 2013-05-02 23:06:05

Re: anyone good with doing math on excel?

#48 2013-05-02 23:12:50

Re: anyone good with doing math on excel?

#49 2013-05-02 23:35:45

Re: anyone good with doing math on excel?

#50 2013-05-02 23:45:23

Re: anyone good with doing math on excel?

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