Whiskerino 2009

CLAME means 'Click My Name.' If you see it, click that users name!

« »
  • posted: November 04 @ 2:38pm
Given the matrix A:
a) Find orthonormal vectors q1, q2 and q3 as combinations of the linearly independent columns of the given matrix A.
b) Write the given matrix A=QR.

Comments

eightyeight says:
{: bonus points if anyone can name this linear algebra procedure. :}
Posted: Nov 4th, 2009 - 2:39pm -
Caronna says:
I failed math every semester.
Posted: Nov 4th, 2009 - 2:42pm -
Ned Kelly says:
my bwain just imploded
Posted: Nov 4th, 2009 - 2:45pm -
super_structure says:
Are you solving for the Eigenvectors? I guess it's been a while that I didn't have software to do that for me.
Posted: Nov 4th, 2009 - 2:45pm -
Pursuit of Hirsute says:
nerd alert
Posted: Nov 4th, 2009 - 2:49pm -
eightyeight says:
{: @super_structure nope, not eigenvectors. in this case, i'm looking for three orthonormal vectors that would make solving Ax=b much more simple, should b be provided. it is a precursor to eigenvalues and eighenvectors though.

i'll give you a hint. if you compute the dot product of q1 with q2 or q3, what do you get? also, what is the length of these vectors? :}
Posted: Nov 4th, 2009 - 2:51pm -
Furricane says:
showoff
Posted: Nov 4th, 2009 - 2:53pm -
juanzo says:
QR Decomposition?

(I went to art school)
Posted: Nov 4th, 2009 - 2:53pm -
mackle says:
[{: what's the deal with the bracketing? seriously? :}]
Posted: Nov 4th, 2009 - 2:58pm -
mackle says:
.:: It's like old school H4X0R decorating ::.
Posted: Nov 4th, 2009 - 2:58pm -
Twisted Sistare says:
solving it doesn't count if you saw the answer on Good Will Hunting
Posted: Nov 4th, 2009 - 2:59pm -
eightyeight says:
{: @mackle it's just my staple for comments. nothing more. ':}' appears to be a bearded smiley, so i ran with it, blocking my comments with an opening beard and closing beard. :}
Posted: Nov 4th, 2009 - 2:59pm -
pcain says:
yeah I went to film school. you got me.
Posted: Nov 4th, 2009 - 3:03pm -
eightyeight says:
{: @juanzo it is QR decomposition. can you give me the name of that decomposition? hint: it's named after the last names of two mathematicians. :}
Posted: Nov 4th, 2009 - 3:03pm -
eightyeight says:
@mackle tbh, i was hoping to start a trend, like clame. i doubt it's working though. you don't like it obviously. :}
Posted: Nov 4th, 2009 - 3:09pm -
super_structure says:
Gram–Schmidt is the only think I could think of that makes sense, and I had to cheat and look that up. Not an algorithm I ever used (or at least that I knew by name).
Posted: Nov 4th, 2009 - 3:11pm -
Johnny Rebellious says:
i'm frightened by this.
Posted: Nov 4th, 2009 - 3:12pm -
super_structure says:
While a structural engineering student, I essentially dealt with matrices of special characteristics. Particularly, stiffness matrices which are symmetric, positive matrices. Therefore, we pretty much used the Cholesky decomposition and the Jacobi method for finding the inverse and Eigenvector(s).
Posted: Nov 4th, 2009 - 3:19pm -
mattyc says:
brain hurts.
Posted: Nov 4th, 2009 - 3:28pm -
eightyeight says:
{: @super_structure BINGO! the Graham-Schmidt process is the QR decomposition i'm demonstrating on the board.:}
Posted: Nov 4th, 2009 - 3:32pm -
mims attack says:
the answer is Yellow
Posted: Nov 4th, 2009 - 3:44pm -
RyRy says:
You and @patrick should be friends.
Posted: Nov 4th, 2009 - 3:47pm -
bobafred says:
you'll never use that shit in real life. just memorize it for the test and then forget it.
Posted: Nov 4th, 2009 - 3:51pm -
Pip says:
What?
Posted: Nov 4th, 2009 - 3:53pm -
jclutch says:
Good Beard Hunting
Posted: Nov 4th, 2009 - 4:00pm -
eightyeight says:
@bobafred actually, i'm hoping i can use this regularly. cryptography, the field i'm going in, uses linear algebra extensively.
Posted: Nov 4th, 2009 - 4:01pm -
bobafred says:
well. i take back my comment, then. good luck!
Posted: Nov 4th, 2009 - 4:04pm -
eightface says:
No more lies... you're actually trying to calculate the current weight of your beard.
Posted: Nov 4th, 2009 - 4:07pm -
mrpbody33 says:
There was once a time long ago I understood that. That time has long passed.
Posted: Nov 4th, 2009 - 4:56pm -
elegant_chaos says:
42
Posted: Nov 4th, 2009 - 5:15pm -
BURNEY says:
I like the word Boolean . That's all .
Posted: Nov 4th, 2009 - 5:16pm -
Ned Kelly says:
that damn Graham-Schmidt process
Posted: Nov 4th, 2009 - 5:33pm -
GrowWithTheFlow says:
I'm much more familiar with the Teddy-Graham process.
Posted: Nov 4th, 2009 - 5:41pm -
Dante says:
rock'n'roll! you get crowned for having math... but who really does gram-schmidt by hand??
Posted: Nov 4th, 2009 - 6:21pm -
david.bean says:
my brain hurts just looking at this.
Posted: Nov 4th, 2009 - 7:22pm -
mynameisjason says:
3 +3 = 6

that's all i need.
Posted: Nov 4th, 2009 - 7:26pm -
mateo says:
I've seen this before. It's an old party trick...the answer is always 12. No matter what matrix A they pick.
Posted: Nov 4th, 2009 - 7:48pm -
Ozzy Nelson says:
i'd be proud of that shit too.
Posted: Nov 4th, 2009 - 8:12pm -
Patrick says:
Hey eightyeight, I didn't know you did math too! I'll post a problem for you later this week.
Posted: Nov 4th, 2009 - 8:12pm -
jracecar says:
5+7=12, but we already knew that, didn't we?
Posted: Nov 5th, 2009 - 12:06am -
Site closed!
Whiskerino. fin.