Darwinbots Forum

General => Off Topic => Topic started by: MightyPenguin on March 11, 2005, 01:27:32 PM

Title: Man Differentiates Circle!
Post by: MightyPenguin on March 11, 2005, 01:27:32 PM
:pengysmiley:  :pengysmiley:  :pengysmiley:  :pengysmiley:  :pengysmiley:  :pengysmiley:
I DIIID IT!!

 :D  :D  :D  :D  :D  :D  :D  :D

( x - a )^2 + ( y - b )^2 = r^2
( y - b )^2 = r^2 - ( x - a )^2
y - b = sqrt( r^2 - ( x - a )^2 )
y = sqrt( r^2 - ( x - a )^2 ) + b
y' = ( a - 2x ) / 2( sqrt( r^2 - ( x - a )^2 ) )

What?

Why are you looking at me like that? I've been wanting to do that all year!

[span style=\'font-size:8pt;line-height:100%\']Ungrateful...[/span]
Title: Man Differentiates Circle!
Post by: Numsgil on March 11, 2005, 01:31:47 PM
When you took the square root you forgot to add the +/-.  What you have there is for half a circle.

There might be some problems in the actual derivate taking too.  I'm just too lazy to double check.
Title: Man Differentiates Circle!
Post by: Zelos on March 11, 2005, 01:33:11 PM
ok, wahts whit this? is that somekinda hard math or what? hope not, else there is no challange for me
Title: Man Differentiates Circle!
Post by: Numsgil on March 11, 2005, 01:34:15 PM
It uses the chain rule for derivates.  Not difficult but sometimes hard to keep it all straight, and you have to know how the chain rule works.
Title: Man Differentiates Circle!
Post by: Botsareus on March 11, 2005, 02:09:40 PM
Is that the circuler paste code for robots from the robot plasment control I sent you?

Use angle generation , Sin and Cos its easyer. , and distance generation after that...
Title: Man Differentiates Circle!
Post by: MightyPenguin on March 11, 2005, 02:23:05 PM
Quote
When you took the square root you forgot to add the +/-.  What you have there is for half a circle.

There might be some problems in the actual derivate taking too.  I'm just too lazy to double check.
I graphed it. It works. Although I did the original derivation on paper and this version one on a keyboard, so I may well have fucked up somewhere. And +/- is really a given with an even root.

But I'm happy.

Bots... ? You what?
Title: Man Differentiates Circle!
Post by: Numsgil on March 11, 2005, 02:31:50 PM
When I graph it on my calculator I get the top half of a circle.

To get the bottom half you have to have the original square root as negative.
Title: Man Differentiates Circle!
Post by: Botsareus on March 11, 2005, 02:36:28 PM
"Bots... ? You what? " = No its not about the robot plasment control

I like the way people talk this days, makes me wana give up on this program.
Title: Man Differentiates Circle!
Post by: Numsgil on March 11, 2005, 02:41:46 PM
Quote
I like the way people talk this days, makes me wana give up on this program.
The problem Bots is that you drift in and out of comprehensibility, as well as tend to pick fights with insulting language.

Sometimes you interpret our inability to understand you as hostility.  That's what happened here.  MP just didn't understand what you were talking about (he isn't involved in coding, so he probably hasn't seen your code).
Title: Man Differentiates Circle!
Post by: shvarz on March 11, 2005, 03:44:38 PM
Quote
Bots is that you drift in and out of comprehensibility,


That is a very good description :)  Sometimes I can understand Bots fine, but other times no matter how hard I try I can't figure out what he's talking about...
Title: Man Differentiates Circle!
Post by: Botsareus on March 11, 2005, 03:48:24 PM
Ok, I will try not to take peoples responses as hostility. I will keep repeating myself until someone understands me, like I did in the general board.
Title: Man Differentiates Circle!
Post by: MightyPenguin on March 11, 2005, 04:51:41 PM
Quote
When I graph it on my calculator I get the top half of a circle.

To get the bottom half you have to have the original square root as negative.
 :rolleyes:

Ah. You somehow managed to miss the fact that a calculator, even the ever popular Graphical Calculator, only gives the positive answer to a square root?

 ;)
Title: Man Differentiates Circle!
Post by: Numsgil on March 11, 2005, 06:08:03 PM
That's because the square root function only returns a positive number by definition.  When you take the square root of a number, you must be sure to remember to add the +/- to get the full set of numbers.

x^2=4
x=+/-2