LessThanDot Site Logo

LessThanDot

A Technical Community for IT Professionals

Less Than Dot is a community of passionate IT professionals and enthusiasts dedicated to sharing technical knowledge, experience, and assistance. Inside you will find reference materials, interesting technical discussions, and expert tips and commentary.

LTD Social Sitings

Lessthandot twitter Lessthandot Linkedin Lessthandot facebook Lessthandot rss

Note: Watch for social icons on posts by your favorite authors to follow their postings on these and other social sites.

Highly Rated Users

Forum
No Posts Rated

Top 50
Given
Received

Forum Statistics

Users
Members:
1879
Members Online:
3
Guests Online:
58

Total Post History
Posts:
81451
Topics:
18716

7-Day Post History
New Posts:
0
New Topics:
0
Active Topics:
0

Our newest member
mwojcik

Other

FAQ
All times are UTC [ DST ]

quadratic puzzle

Mind Boggling Puzzles, to keep that grey matter in shape...
Forum rules
Always post answers in a "Hidecode" tag, so that others have a chance to answer the question too.
Please wait...

quadratic puzzle

Postby phillip1882 on Mon Mar 14, 2011 11:59 pm

"everyone" knows how to get the line of best fit. you challenge is: given a set of data, find the quadratic equation of best fit :-)
*hint* a bit of calculus can go a long way.
I'll post my solution next week if no one gets it.
User avatar
phillip1882
Apprentice
Apprentice
LTD Bronze - Rating: 22
 
Posts: 19
Joined: Mon Mar 14, 2011 11:05 pm
Location: florida
Unrated

Re: quadratic puzzle

Postby vongrunt on Tue Mar 15, 2011 12:44 am

In other words, for any set of (x, y) points we must find 2nd degree polynomial (a*x^2+b*x+c) that gives the smallest error?
How many SEO experts do you need to change a lightbulb lightbulbs buy light bulbs neon lights sex p0rn
User avatar
vongrunt
Senior Apprentice
Senior Apprentice
LTD Bronze - Rating: 103LTD Bronze - Rating: 103LTD Bronze - Rating: 103
 
Posts: 151
Joined: Thu Mar 27, 2008 3:21 pm
Location: Space sector 2814
Unrated

Re: quadratic puzzle

Postby phillip1882 on Tue Mar 15, 2011 1:41 am

exactly :-)
User avatar
phillip1882
Apprentice
Apprentice
LTD Bronze - Rating: 22
 
Posts: 19
Joined: Mon Mar 14, 2011 11:05 pm
Location: florida
Unrated

Re: quadratic puzzle

Postby Thirster42 on Tue Mar 15, 2011 3:12 pm

vongrunt wrote:In other words, for any set of (x, y) points we must find 2nd degree polynomial (a*x^2+b*x+c) that gives the smallest error?


pass!

;)
Ask three DBAs a question, and you’ll get four different answers.

-Brent Ozar
User avatar
Thirster42
Guru
Guru
LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517
LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517
 
Posts: 4646
Joined: Tue Nov 11, 2008 5:49 pm
Location: Jefferson City, Mo
Unrated

Re: quadratic puzzle

Postby Emtucifor on Tue Mar 15, 2011 9:18 pm

I'm very interested but don't have time and don't really remember enough calculus. I know how to integrate... but exactly how doing that is going to help with, say, 50 random points, I don't know.
God cries a little bit every time someone builds a database.
User avatar
Emtucifor
Guru
Guru
LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033
LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033
LTD Gold - Rating: 1033
 
Posts: 2835
Joined: Fri May 30, 2008 9:30 pm
Location: Bellingham, WA
Unrated

Re: quadratic puzzle

Postby Thirster42 on Tue Mar 15, 2011 10:13 pm

i think this one might be a little over our heads :-D

the highest math i took was trig, and i didn't pay a whole lot of attention (senioritus)
Ask three DBAs a question, and you’ll get four different answers.

-Brent Ozar
User avatar
Thirster42
Guru
Guru
LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517
LTD Silver - Rating: 517LTD Silver - Rating: 517LTD Silver - Rating: 517
 
Posts: 4646
Joined: Tue Nov 11, 2008 5:49 pm
Location: Jefferson City, Mo
Unrated

Re: quadratic puzzle

Postby Emtucifor on Wed Mar 16, 2011 12:37 am

I took calculus BC and got a 5 on the calculus AP exam. I love math. With a few refreshers, I'd be back in the game. :)
God cries a little bit every time someone builds a database.
User avatar
Emtucifor
Guru
Guru
LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033
LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033
LTD Gold - Rating: 1033
 
Posts: 2835
Joined: Fri May 30, 2008 9:30 pm
Location: Bellingham, WA
Unrated

Re: quadratic puzzle

Postby MHGlassman on Wed Mar 16, 2011 1:53 am

Emtucifor wrote:I took calculus BC and got a 5 on the calculus AP exam.


I did the same, then pursued a mathematics degree in college. But 30+ years later, I'm certain I couldn't derive the equations to do solve this now.

Good thing others have done this for me already:
Code is hidden, SHOW

And others have previously programmed this as well:
Code is hidden, SHOW

I'm curious to see if Phillip gives us similar solutions or if he has another method in mind. In the meantime, thanks for taking me back to my mathematic roots -- pun intended -- for an afternoon, Phillip! =D>
"The trouble with quotes on the Internet is that it's 
difficult to determine whether or not they are genuine."
-- Abraham Lincoln
User avatar
MHGlassman
Senior Apprentice
Senior Apprentice
LTD Bronze - Rating: 115LTD Bronze - Rating: 115LTD Bronze - Rating: 115
 
Posts: 72
Joined: Tue Jun 17, 2008 7:58 pm
Location: Englewood, CO, USA
Unrated

Re: quadratic puzzle

Postby Emtucifor on Wed Mar 16, 2011 7:48 am

MHGlassman wrote:
Emtucifor wrote:I took calculus BC and got a 5 on the calculus AP exam.

I did the same, then pursued a mathematics degree in college. But 30+ years later, I'm certain I couldn't derive the equations to do solve this now.

I cannot do it now either. Thus the need for refresher courses! Though for me it's been 21 years.
God cries a little bit every time someone builds a database.
User avatar
Emtucifor
Guru
Guru
LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033
LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033LTD Gold - Rating: 1033
LTD Gold - Rating: 1033
 
Posts: 2835
Joined: Fri May 30, 2008 9:30 pm
Location: Bellingham, WA
Unrated

Re: quadratic puzzle

Postby chrissie1 on Wed Mar 16, 2011 8:22 am

Thirster42 wrote:i think this one might be a little over our heads :-D

the highest math i took was trig, and i didn't pay a whole lot of attention (senioritus)


No not over our heads just yours ;-). I have one tucked away somewhere just need to get it out, wich isn't going to happen any time soon I'm afraid. It's also better known as curve fitting. Some sample data would be nice so people can compare their solutions eassier.
pink fuzzy slippers
User avatar
chrissie1
Senior Guru
Senior Guru
LTD Gold - Rating: 2135LTD Gold - Rating: 2135LTD Gold - Rating: 2135LTD Gold - Rating: 2135LTD Gold - Rating: 2135
LTD Gold - Rating: 2135LTD Gold - Rating: 2135LTD Gold - Rating: 2135LTD Gold - Rating: 2135LTD Gold - Rating: 2135
LTD Gold - Rating: 2135LTD Gold - Rating: 2135
 
Posts: 9475
Joined: Wed Oct 10, 2007 7:18 pm
Location: Belgium
Unrated

Re: quadratic puzzle

Postby vongrunt on Mon Mar 21, 2011 8:38 pm

OK. Extra milk and cookies for anyone who writes generalized algorithm (curve fitting with nth degree polynomial) :)
How many SEO experts do you need to change a lightbulb lightbulbs buy light bulbs neon lights sex p0rn
User avatar
vongrunt
Senior Apprentice
Senior Apprentice
LTD Bronze - Rating: 103LTD Bronze - Rating: 103LTD Bronze - Rating: 103
 
Posts: 151
Joined: Thu Mar 27, 2008 3:21 pm
Location: Space sector 2814
Unrated

Re: quadratic puzzle

Postby TinnedTuna on Wed Aug 22, 2012 11:37 am

The answer is to apply existing techniques and a small transformation:

Code is hidden, SHOW
TinnedTuna
Newbie
Newbie
 
Posts: 1
Joined: Wed Aug 22, 2012 11:19 am
Unrated