LU Decomposition Method: Decomposing a Matrix Example: Part 2 of 2

[raffa123able]

very well set out, I appreciate this tutorial very much

[arqi25]

Hi Sir, I understand what you did there, but how would you use LU decomposition to solve this problem [1 1 -1 ] [x1] [-1] 2 -1 1 x2 = 4 1 -1 -1 x3 1

sorry about the brackets they r supposed to be long! Thank You.

[numericalmethodsguy]

@arqi25 One would decompose the coefficient matrix the same way as the example. You decompose square matrices, not sets of equations. In this case A=[1 1 1; 2 -1 1 ; 4 1 -1], X=[x1, x2 x3], C=[-1 4 1]. First decompose A=LU, then solve LZ=C, and then UX=Z.

Go to numericalmethods(dot)eng(dot)u­sf(dot)edu; click Keyword. Click LU Decomposition. Read textbook chapter.

Go to numericalmethodsguy channel on YouTube, click playlists, click LU Decomposition & see the 2nd video.

[devinep5]

What if the matrix i am given equals something?

[numericalmethodsguy]

@devinep5 Give me the problem statement. Remember if AX=C is a set of eqns, the decomposition of A just depends on A, not on C.

[gelidusgaudium]

Thank you!

[TheDanydanial]

Thanks a lot..really helpful..now i know how to get L by just using the multiplier which can be got from U =)

[MetallicOrange]

Excellent! Extremely helpful!

[coljackdripperofburp]

thank you! it would have taken me days to learn that on my own by book!

[wilcatesondwong]

THANK YOU SO MUCH!!

[TheKb07]

Thanks alot sir.. u made this problem very easy

[SHDTRAN]

Good explanation!

[emerickmage]

why is a vid of some dumb cunt shaking her ass top of the suggestions column? , GTF BITCH IM DOING MATH

[numericalmethodsguy]

@xgokkusagix It can only be used on a square matrix.

[samia7756]

ok cudnt kill it ..but gave it some punches..hoping for 70% lets see :D lol

[hussainhassain]

@samia7756 softtttttttttttttttttttttttttt­ttttttttttt :P u shoulda killed it 

[samia7756]

two thumbs up for this lecture :D now gonna go to the quiz and kill it insh'Allah !!

[vfranco06]

Very nice clear explanation of LU decomposition. I'm currently in a grad class and we are covering this topic and I could not follow the professor. I watched this video once and got it immediately. Thanks!

[RahaSFU]

nice and clear. Thanks. I envy your students, they are so lucky

[andronicusyyz]

So this was pretty good in explaining LU decomposition. However, what is the use of this in terms of solving a system of equations? Why would one use this method over alternatives such as Gauss-Jordan Inversion or Cramer's Rule?

[numericalmethodsguy]

@andronicusyyz It is all about computation time. LU Decomposition takes less computation time if you have to solve many sets of eqns with different RHS or if you are finding inverse of a matrix. Go to numericalmethods(dot)eng(dot)u­sf(dot)edu, and click on keyword, click on LU decomposition, annd see the textbook chapter, and go to page 2. You will have the complete answer!

[acomodo92]

@numericalmethodsguy i think your not allow to use a cumputer when you take a exam so you better learn it by this way!!

[ProxySpam]

@andronicusyyz It's useful to pass your math exam lol

[ProxySpam]

Please add captions as soon as possible, I am most of the time in a library and I have no sound on the computer. Takes me time to figure out what you're doing ^.^

[numericalmethodsguy]

@ProxySpam It may be time to get some headphones. Captioning is very expensive and time consuming process. My university is helping me to put this on iTunes and most probably will be close captioning it. But it is going to take a while.

[ProxySpam]

@numericalmethodsguy Thats ok I got the method. Clear even with no sound lol

[trinijuice2008]

yo tandoori man, very clear, very precise. thanks.

[milindrakulugammana]

Crystal clear. Thank you very much.

[cacashit23]

hahahah i cant believe LU decomposition was this easy.....thank you professor for sharing this video

[jcdmb]

fucking great! I have searched in 3 good book this method and could not find any. Thanks a lot man!

[dantheactionman]

Very helpful thanks

[mpbaker22]

pretty useless for first 10 minutes. Skip to the last 2 minutes and the explanation is pretty good.

[vitfc]

Great video! Subscribed !

[alice1cmd]

subscribed!

[tweakedmofo]

Thank you so much, I'll be putting this info to use tomorrow

[raphaelgentile450]

Thanks!!

[shiringham]

You ROCK

[eajustin06]

word my finals in 3 hours hah ima gonna passsssssssssssssssssssssss woooooooooorddddddd

[fusion2x]

awesome, clearest lecture about this ever!

[iwashungry]

Very helpful!

[SoumyaGangula]

jus superb...... thanks for uploading it......

[Crayfish1010]

outstanding!!!

[phowaiwin]

Awesome!. I very much appreciate him. This is crystal clear.

[rtalbert235]

Thanks for this very clear exposition. I'll be sharing this with my own linear algebra students.

[numericalmethodsguy]

@rtalbert235 Please email me the university you are taking the course at!

[divinenuker]

AWESOME!

[Peeanorun]

awesome! he did such an awesome job explaining LU Decomp. Thanks!

[barryon]

Brilliant! I'm panicing and i have to say that i have this nailed now because of this vid!!

Brilliant teacher.

[fiwel]

Thank you man. Very good video. Maybe I'll pass this exam after all? :)

[yunjizzle]

very clear

[jiminikiz]

really well presented, awesome instructional video

[zsiuramCie]

Great teacher. Thanks for this vid.

[Tordre]

Thank you i have my exam in 2 hours this is a great video.

[ramjam19]

hands down, you are the best!!! Thank you very much.

[pangolish]

great! helped me a lot