Linear Algebra: QR Factorization

[Chiefpilot]

I've just watched 4 different videos of this same topic and you explained it the best. Thanks, I have a final tomorrow.

[gaiusjuliuscaesar]

This video explained QR factorization better than my professor did in half the time of his lecture. Thanks!

[dennisalexander]

Cool man! Your “easy” process is true and proven

[raduchivu]

Hello, does this algorithm works for a Square Matrix ?

[PRAKASHKUMAR-qxtq]

thanks bro, its a great video and very helpful.... :)

[rajithodlme]

thanks for the videos, any videos on jacobi/subspace iteration & householder technique?

[LAnonHubbard]

Hi, thanks for the video. It was helpful but would've been cleaner if at around 4:00 it wasn't written down that u_2 = RHS where RHS is not a unit vector.

[AssassinGrudge]

Thx a lot it real help, Linear Algebra is so important in Computer graphic and computer vision and i forget about it XD so ur video are helping thx again

[tpat]

I am sorry but,
Q is not orthogonal.

It is not left and right inverse with Q transpose.

You get
Q^TQ = I (so it holds for the usage in this example)
but
QQ^T !=I


To be orthogonal Q would need to be a square matrix.

[piyushabhatt]

Could you please recommend me the textbook you have used for QR factorization?

[ashleyp]

whats the algorithm for u? how do you calculate u_3?

[nbk]

why did you divide length of m1 for u1 and length of u2 for u2?

[s]

when i use matlab it comes out the exact same number except the sign, why is that?

[Heeeeeeeeeyz]

Hello,
Can someone tell me how to get U3 .. if we have 3*3 (M) matrix..??

[Squiel]

Good explanation and cute teacher. what else can i ask? haha

[hyena]

If you forget to divide u2 by its length, please make sure you rewrite that. There is nowhere in scientific computing where "u2=a, u2=b" is allowed.

[madhuritomar]

upper triangle matrix is only possible with square matrix ... i

[stumashaal]

bad call using a semi orthogonal matrix in a lesson that's meant to explain QR factorization. At least mention it.

[geekiayanagejayawardena]

I think your u2 calculation is missing a ||u1|| under the <m2.u1>u1.. so it should be u2 = m2 - (<m2.u1>/<u1.u1>).u1 right?

[MrWolfgangWeiss]

Try multiplying your Q by R and we do not get our M so something you did is wrong :(