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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

Hi;

Check this vid out at

http://www.youtube.com/watch?v=SuOIpJnn888

It is about validating a simulation but covers more in an interesting way.

Isn't it amazing how when he writes 3.14161124, a number that differs from π by a mere .0000185 and asks his class to identify it we get an unearthly silence. I mean you can not even here anyone snoring. Just silence. Wunderbar!

I like the way the professor brings a doggie bag of treats to class and throws them to any kid who has the courage to answer a question. Does this provoke a plethora of answers in a Pavlovian way? Nope!

I love the whole explanation of Hooke's law. Professor shows a scatterplot that resembles a sausage or maybe a centipede and his comatose class is supposed to imagine the straight line in there. Not likely.

There are two kids who are getting all the treats in the bag save for the ones the portly instructor is keeping for himself. Both these kids must resemble Jabba the hut by now with all that chocolate they are consuming.

All in all he makes some good points about experimental data. Okay, back to the vid, I am half way done.

Wait, a third kid just got a treat, this Pavlov guy was really on to something!

Here is a blooper,

It is just as easy to fit a quadratic to the experimental data as a line.

Only if you have a package helping you!

I think the prof slips up with his proof that a quadratic fit will always result in a lower R^2. This maybe true but not for the reason he gives.

Very good explanation for overfitting but numerical stability is yet another reason why you should not do it. Particularly if you are using as a basis ordinary powers of x.

Two thumbs up for the vid!

*Last edited by bobbym (2013-02-14 02:12:32)*

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

I like the way he writes lowercase "t".

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

What is so strange about it?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

Nothing. I like the way he writes it.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

You like the little monkey tail on the bottom?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

His "t" doesn't have that "tail".

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

25:30 in. In the word Fit you will see the monkey tail.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

There is one in "Reality" a bit before. Just noticed it. But, no, I like the tailless t's.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

Can you point out one t that has no tail?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

First two t's in "statistical" at 08:35.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

Hmmm, but then look at validity. A big tail!

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

Yes, but I like the ones without the tails.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

What did you think of the video?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

I really do not know what to think. You'd think at least someone would laugh at him throwing candy at students...

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

Could be a class of zombies. Did you learn anything by watching it?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,000

Nothing more than the stuff you've been telling me.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,902

Well then you are ready for MIT! The commuting might be a little difficult.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

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