Algodoo

Well, actually it cannot work the way that you depict in the scene. Here's why: In chess, en passant ( French: "in passing") describes the capture by a pawn of an enemy pawn on the same rank and an adjacent file that has just made an initial two-square advance. The capturing pawn moves to the square that the enemy pawn passed over, as if the enemy pawn had advanced only one square. At that point the captured pawn is removed from play. That's why it can happen only once, not infinitely as your scene depicts.

Sorry...

Oh, one more thing... The chessboard shown in your scene must be rotated 90 degrees in order to play a correct game of chess. (The lower-right hand square must be white, not the dark color as you have it). That's a common mistake that many inexperienced chess players make, especially here on Algobox).

Sorry again...

a_bored_coder -- Hey no problem. Algodoo is here for fun, and if we can't have fun (while occasionally getting educated) then it's not worth doing. Some of my own scenes are rather silly, and I've posted them just to get some laughs. I love this stuff!

You're welcome.

a_bored_coder -- I now see what the problem is.... You used a checkerboard pattern that has 64 by 64 squares. That's a total of 4096 squares!
A chessboard has 8 by 8 squres (a total of 64). If you wanted to be correct, you can mask off the extra squares or simply delete them. Then you will have a proper chess board.

This is just a suggestion. It's totally up to you what you do with your own scenes.

Oh, Okay. Anyway, it's a cool animation that you did!

Yeah, it's home-grown Thyme script, so I did not bother to check my code for all possible exceptions.

Interesting scene, but either I'm not using it correctly or it doesn't work for some reason. I set the range and depth as instructed but then nothing happens. Where are the results displayed? Also, what is "PBv1"? ...and lastly, what is "Algomatic Computer Systems"?

Yes, that's known as "regression to the mean". You can run the scene a thousand times (or a million times if you don't die during the test), the middle bin will almost always receive most of the balls. The resulting shape of the stacks of balls form a Gaussian (bell-shape) curve, although technically the distribution is a binomial distribution because of the binary nature of each peg and how they are configured.

CPJhute -- No, it's not because I don't know how to use it! I'm not stupid and I can follow directions. I clicked Run, and then I changed the range to 0-10, and the depth to 5 (I wanted to keep it simple for now). After I did those things, absolutely nothing happened. I don't think your scene works, unless you are leaving something out of the "simple" instructions.

After looking through the Thyme script in the green box, I see that there are "print" statements which means that certain things get printed to the Algodoo console (F10 key). Yup, sure enough.... that's where the results of this prime number finder scene gets written. So, yeah... CPJchute DID leave out one important step in his "simple" instructions!

Okay, now things are working. It helps to have ALL the instructions.

Now I can focus on playing with primes!

I got the original idea from a scene by user "Chemist" called:

Time control beta

Click the link and take a look at his script!

Oh, one hint for ya.... There are some hidden lasers and a hox to the left of the text box and slightly above the plane. Those are for decoding key-presses. It's how we did it before "keys.isDown" command was implemented in Algodoo.

Thank you.

s_noonan - Thanks for your concerns and ideas. No, the scene is not "perfect" at all. I just whipped something together for people to play around with. If I were making this for a government agency or the U.S. military, then of course it would be much more accurate and precise. Concerning your question about making sure each peg has binary probability, I did at first, but, as you mentioned, the balls would occasionally get stuck at the exact center of their X position. So, by allowing a tiny bit of "slop" in their positions, that was no longer a problem. The worst offender in that regard was the first peg at the top of the triangle because the balls are at their lowest velocity at that point and they typically fall straight down. The other pegs typically receive the balls after they were deflected by a higher peg at a 45 degree angle. That's why I gave that particular peg a pointed head. (LOL)

More: Concerning your question (#3) about units, the standard deviation value represents the same unit of measurement that any person playing this scene used for the heights of the balls in the bins. For example, if you measured the ball heights in centimeters, then the standard deviation is also in centimeters. It quantifies the average distance of the ball heights from the mean height, in whatever unit you originally measured them in. So, if your measurements were in inches, meters, or any other unit, the standard deviation would be expressed in that same unit.

Q: I don't understand the formula. Do you have a source?

A: The following was copied from the Khan Academy website:

Here's how to calculate population standard deviation:
Step 1: Calculate the mean of the data—this is‍
in the formula.
Step 2: Subtract the mean from each data point. These differences are called deviations. Data points below the mean will have negative deviations, and data points above the mean will have positive deviations.
Step 3: Square each deviation to make it positive.
Step 4: Add the squared deviations together.
Step 5: Divide the sum by the number of data points in the population. The result is called the variance.
Step 6: Take the square root of the variance to get the standard deviation.

I only recently learned about the math behind the Galton Board and so I may not be applying it correctly, especially with my weird version of it that uses a single ball that keeps repeating until N balls have fallen into bins. It's different than a bunch of balls simultaneously falling and interacting with each other. If you are fairly certain that I did something wrong, please let me know what it was and I'll correct it. Thanks...

By the way, I watched a video about a guy who was toying with the idea of a 3D Galton Board! He realized that actually building one would probably be physically impossible but he thinks he figured out the math for it. I wouldn't even think about attempting such a thing in Algodoo!

What do the red dots in each bin represent?

AI is absolutely correct, I just didn't quite know how to put it into words that made sense. I would be happy if he (ummm, I mean "it") could fix it! Thanks for your help with this, s_noonan.

Ahhh... makes sense! Thanks.


Edit: Would it also make sense to display the resulting number of balls in each bin after a run (like I did in my Galton Board scene)? That would be useful for people who may want to confirm your calculation results with an external calculator.

Great! I do have Copilot so I'll give that a try. Thanks again.

That was quick!

I noticed that when I alter the "No. of rows" value, the "Ideal Std Dev" value changes immediately, without clicking the "OK" button, regardless of the number of balls selected. Is that correct?

Wow, Bill, you sure do like toilets!

I searched for "idealized standard deviation" and it appears that the concept is used for sports events like baseball or football games. Also, according to the definition that I found, one of the terms in the equation is the actual SD. Here is a quote from one of my sources: The “idealized” standard deviation (ISD) is the quotient of the actual standard deviation of results in a season divided by 0.5/N, where N is equal to the number of games in a season.

This is the first time I heard of idealized standard deviation, and therefore I don't fully understand its purpose.

Erm, that's the way I spelled it in my comment!

Oh, sorry. I should have looked at your name more closely!

Okay, Little. Just let me know when you are ready to make the change and I'll get the process in motion. What will your new name be?

Don't worry about anyone sending hate your way. If that happens, simply report them and I will take care of the rest!

Just wondering, were you Lailou12 before you became hmnidp09?

@misterlove123456 -- It may seem dumb to you because you probably know little or nothing about the history of Algobox and Algodoo. I registered here back in 2012 (probably when you were still in diapers). Back then there was competition and collaborations between users. If people were allowed to register more than one account, they would be able to cheat by boosting their own ratings through their multiple accounts. We no longer have that kind of competition or collaborations but the rule remains in place. Actually, I can't think of any good reasons to register more than one account. If a person is sloppy, lazy, or stupid, having more than one account won't make them any less sloppy, lazy, or stupid.