Buffon's Needle

Devreugkx · Posted: 11 May 2012 10:10:21 am Post subject: Buffon's Needle

Hi,

I was trying to make a simulation of Buffon's Needle on the TI-84+.
But I couldn't make it.
Maybe someone else can?

What's Buffon's Needle?
http://en.wikipedia.org/wiki/Buffon%27s_needle
http://mste.illinois.edu/reese/buffon/bufjava.html

merthsoft · File Archiver Joined: 09 May 2010 Posts: 2735

Why did you give up? Did you come across a problem you couldn't get past? Why not try to make it and ask here if there's something hanging you up.
_________________
Shaun

Aes_Sedia5 · Posted: 11 May 2012 10:46:37 am Post subject:

We have many people here that can help. I have found in most situations, it is one or two small things that you are missing.
_________________

KermMartian · Posted: 11 May 2012 11:53:11 am Post subject:

I second what both of these two said. Since you're posting in the TI-BASIC help forum, it would seem appropriate for us to help you through whatever is making you be stuck. Are you having trouble imagining the overall structure of the program in TI-BASIC, or some specific technical detail?
_________________

Devreugkx · Posted: 11 May 2012 02:22:20 pm Post subject:

I aspecially have a program with how I should program how the needle should fall.

I thought about random generate an X and Y starting coordinate and than an X an Y end coort. But than the line could be any length.
So I thought about also generate a number between 0 and 360 and draw a line (=the needle) from begin point in the generated direction.
But I have no idea how I should make that AND let the length be always the same length.

To check if the needle crosses one of the lines, I thought I could use the Pixel/Point check command. But don't know how to configure that one, because I never used it.

That are myt problems so far.

KermMartian · Posted: 11 May 2012 02:40:17 pm Post subject:

Well, if you have a starting point (x1,y1), a length n (I chose n instead of l because l looks like 1 in monospaced font), and an angle Θ, then the math works like this:

Kaslai · Member Joined: 16 Nov 2011 Posts: 172 Location: ???, WA

Remember, when dealing with trig functions, pay attention as to if the calculator is in degrees or radians.

As far as detecting an intersection, this can be found by determining which strip either point is in and comparing.
given W = width of the strips and X1, Y1, X2, and Y2 are the relevant coordinates of the points, an intersection can be found with the inequality

Devreugkx · Posted: 13 May 2012 10:00:55 am Post subject:

@KermM, the code works, thanks!

@Kaslai, the iPart function is really helpful, but sometimes it gives a 'false' signal...

KermMartian · Posted: 13 May 2012 11:49:00 am Post subject:

What do you mean by that? Did you write the two cases, for horizontal and vertical strips, as Kaslai said? Or just the one?
_________________

Devreugkx · Posted: 13 May 2012 11:56:30 am Post subject:

I made a little mistake while programming, it's works fine now!
After about 500 needles, Pi was 3,18.

KermMartian · Posted: 14 May 2012 09:35:40 am Post subject:

Devreugkx · Posted: 14 May 2012 11:02:12 am Post subject:

I will!