Matrix Transpose and the Four Fundamental Subspaces

Фильм және анимация

3Blue1Brown's Linear Algebra Videos: • Essence of linear algebra
Geogebra (Used for making plots):
Relevant StackExchange Answer: math.stackexchange.com/a/37402
Also relevant Quora Answer: www.quora.com/What-is-the-geo...
Notes
[1] By "gives a sense", I mean contains vectors that can form an orthogonal basis for the components of the vectors not in the ranges.
[2] It isn’t really legal to plot R^2 and R^3 on the same set of axes like this, R^2 and R^3 are completely different spaces, but I’m showing them like this to provide some intuition and justification for all three parts of the SVD.

Пікірлер: 54

  • @martinbiroscak3487
    @martinbiroscak34875 ай бұрын

    This solved about 5 years of my confusion in 10 minutes. Thank you so much.

  • @jarthur8428
    @jarthur84283 жыл бұрын

    How the hell you only have 13 subs.... Is one of the best explanation I ve found!!!!

  • @njt3773
    @njt37732 жыл бұрын

    The best explanation of transpose matrix on the internet. Very clear voice and simple visualizations!

  • @Kralasaurusx
    @Kralasaurusx3 жыл бұрын

    I love how geometric and intuitive this explanation is. It seems as though a lot of math lectures and explanations often end up deep into the symbols that the higher-level intuition and meaning gets lost. Not that symbolic explanations are bad per se, but it definitely helps to be able to understand and visualize things at a high level like this. Thanks for the excellent explanation.

  • @moseschuka7572
    @moseschuka75723 ай бұрын

    Super helpful, this is not usually explained in textbooks. Authors just assume you know what is happing. Couldn't find better explanation elsewhere. Thanks a lot.

  • @speedbird7587
    @speedbird75875 ай бұрын

    Thank you sir, You really provided a good visualization for how matrices distort/stretch data. A_transpose and A_dodge rotate the date in same manner but magnify differently! Visually , since they have the same rotational effects, the orientations of the basis vectors does not change, so their subspaces, particularly the null space and column(range) spaces remain intact. But still A_transpose and A_dodge distort data shapes differently!

  • @harryhuang1999
    @harryhuang1999 Жыл бұрын

    Amazing job Ben. Explained with such conciseness and clarity

  • @meharjeetsingh5256
    @meharjeetsingh52563 жыл бұрын

    Thank You Ben! It was a lovely experience watching your video.

  • @natonion1154
    @natonion11542 жыл бұрын

    This is really good, thank you so much. Was confused by the fundamentals of subspaces and what do they mean in terms of visualization.

  • @ETeHong
    @ETeHong2 ай бұрын

    What a incredible video you upleaded!

  • @gp2111
    @gp21119 ай бұрын

    Nicely done. Thank you for this.

  • @varunsharma3485
    @varunsharma34859 ай бұрын

    Loved IT. Best video on transpose on youtube.

  • @pelegsap
    @pelegsap10 ай бұрын

    Incredibly good video. Thanks!

  • @phizmaster5233
    @phizmaster52334 жыл бұрын

    Wow! You are such a great teacher!!!!

  • @pauselab5569
    @pauselab55694 ай бұрын

    A homomorphic function maps K^n to K^m sending each element of K^n to a subspace of K^m. A^T the transpose maps K*^m to K*^n sending each element of K*^m to a subspace of K*^n. where K* is the dual space of K and it must satisfy A^T(f)= f(A), f is a linear transformation in A^T. the 4 spaces are the kernel and the image of A and A^T. now it happens that K is always isomorphic to K* if both n and m are finite natural numbers. so you can kind of think of A^T as a function from K^m to K^n. in the example: A maps R^2 to a line in R^3, ima(A) and ker(A) are both lines. A^T maps R*^3 to a line in R*^2, ima(A^T) is a line and ker(A^T) is a plane.

  • @christophercrawford2883
    @christophercrawford28836 ай бұрын

    Nice geometric intuition. Note that the SVD actually rotates the image and coimage from/to the x axis (or xy-plane, etc) so the diagonal matrix can do its job. In general, 'rotation into the same direction as the image' is not well-defined. You could extend your intuition to motivate A+ = (A^T A)^-1 A^T, since A^T A maps the image back to the image, swished around.

  • @hideyoshitheturtle
    @hideyoshitheturtle2 жыл бұрын

    3:10 “Applying A squishes R^2 like this” doesn’t click in my head. The matrix A is a mapping from R^2 to R^3, so I’m not sure why the output vector is discussed in R^2 instead of R^3…?

  • @miikavuorio9190

    @miikavuorio9190

    2 жыл бұрын

    The way I understand it is simply that he's breaking down the transformation of A into two steps, first one which squishes R^2 and then another which maps that squished R^2 into R^3. It was simply a way of explaining it in order to make the transformation easier to intuit where the null space of A is

  • @pauselab5569

    @pauselab5569

    4 ай бұрын

    this is a result from the first isomorphism theorem and homomorphism decomposition. A is a homomorphism from R^2 to R^3. ima(A) is given in this example to be a line. R^2/ker(A) is isomorphic to ima(A) which shows that ima(A) is also a line. now do a homomorphism decomposition. Function 1 is a homomorphism from R^2 to R^2/ker(A) and function 2 is an isomorphism from R^2/ker(A) to ima(A). the composition of function 1 then 2 is the same as the homomorphism A. you just break down the function which makes it easier to understand.

  • @_outfit_ideas_
    @_outfit_ideas_3 күн бұрын

    Thanks a lot!!!🎉😊

  • @tenebreonlabs
    @tenebreonlabs4 жыл бұрын

    This was helpful, thanks!

  • @prashantgupta8804
    @prashantgupta88044 жыл бұрын

    Wow.... Superb VIdeo.... Best video ever seen.. : 11:06

  • @kangmintan5096
    @kangmintan50963 жыл бұрын

    Great video! Got it now!

  • @adityanjsg99
    @adityanjsg993 жыл бұрын

    Too overlooked channel. Instant sunscribe!

  • @minhducphamnguyen7819
    @minhducphamnguyen78194 ай бұрын

    I understand up to the point where you're breaking down how to transform the R(A+) subspace to the R(A) subspace. Why does the 1st rotation V^T have to be orthogonal?

  • @meharjeetsingh5256
    @meharjeetsingh52562 жыл бұрын

    Can you also explain the difference between transpose(A) and inverse(A)?

  • @133839297
    @133839297 Жыл бұрын

    Great content!

  • @shashikantkumar5095
    @shashikantkumar50953 жыл бұрын

    nice, i somehow got a feel of what transpose means

  • @VolumetricTerrain-hz7ci
    @VolumetricTerrain-hz7ci3 ай бұрын

    There are unknown way to visualize subspace, or vector spaces. You can stretching the width of the x axis, for example, in the right line of a 3d stereo image, and also get depth, as shown below. L R |____| |______| This because the z axis uses x to get depth. Which means that you can get double depth to the image.... 4d depth??? :O p.s You're good teacher!

  • @tuongnguyen9391
    @tuongnguyen9391 Жыл бұрын

    Damn this is so good !

  • @nitinjain1605
    @nitinjain16052 жыл бұрын

    You are the only one who is clearing this transpose doubt....i understand few things here But there is one doubt While you explaining the both range on same space through the example I didnt get the point why the vector length on R(A+) is different from R(A) Could you clear this doubt ? I know it will be not easy in text to explain but if you can with same video you can include example in more defined way Really thanks for this video i learned a bit more today

  • @cocoabutter5888

    @cocoabutter5888

    Жыл бұрын

    A might be scaling vectors as well when moving from R2 to R3. So the length of a vector in R(A) may not be the same as the length before the mapping to R3 (i.e, a vector in R(A+)) is my guess.

  • @borissimovic441
    @borissimovic44113 күн бұрын

    Can someone please explain, if you can, how can a length which is 1D “a line” (Length of cross product vector) be equal to the area which is 2D, how can something that is 1 dimensional be equal in length to the Area which is 2 dimensional (and has width plus length as information)?

  • @Gaygurke
    @Gaygurke2 жыл бұрын

    Realy cool!

  • @Kriojenic
    @Kriojenic4 жыл бұрын

    What did you use to record this?

  • @pabloballesteros3571
    @pabloballesteros3571 Жыл бұрын

    8:10 "V is an ortogonal/orthonormal matrix" why V has to be ortogonal? Every shear on the plane can be represented with an ortogonal matrix?

  • @omridrori3286
    @omridrori32863 жыл бұрын

    And if you can maybe to make a video in this style which more focus about the transpose matrix i dont think i really understand it well and in a short exploration in the internet it’s look like i am not the only one

  • @sheffer100
    @sheffer1003 жыл бұрын

    Great video! but I that A should be [[-1,1,1], [-1,1,1]] shouldn't it?

  • @Andrew-fg3jj

    @Andrew-fg3jj

    Жыл бұрын

    I feel the same

  • @ManojKumar-cj7oj
    @ManojKumar-cj7oj3 жыл бұрын

    Why don't you make more videos buddy ❤️

  • @yybbhn
    @yybbhn2 жыл бұрын

    Just so I'm certain, Range as used in this video is functionally the same as column space correct?

  • @It_is_Jake

    @It_is_Jake

    2 жыл бұрын

    Range could be of column space or of null space. Range is the number of dimensions that column or null space has.

  • @It_is_Jake

    @It_is_Jake

    2 жыл бұрын

    So, I feel you are not right. Range is a characteristic of column space, row space, null space, or left null space.

  • @varshneydevansh
    @varshneydevansh5 ай бұрын

    ❤❤

  • @Matt-yu8xc
    @Matt-yu8xc9 ай бұрын

    at 2:13...why isn't it R^3? The line is in R ^3, not R^2.

  • @omridrori3286
    @omridrori32863 жыл бұрын

    3:10 Why ? Why all the vectors in r2 goes like that it’s not clear to me ... All besides that an amazing explanation

  • @omridrori3286

    @omridrori3286

    3 жыл бұрын

    I think it’s not true because for example (1,2) Is going to (3,3,3) it is not going to (1,1) before

  • @miikavuorio9190

    @miikavuorio9190

    2 жыл бұрын

    Yea, it's not a mathematically rigorous explanation of A. However, I believe it is worded like that to make it easier to intuit where the null space of A lands. He breaks down A into two steps, firstly the squishing of R^2 to the range of R transpose and then the mapping of that to the range of A

  • @cachah216
    @cachah2164 жыл бұрын

    YOU ARE FUCKING AMAZING

  • @Gaygurke
    @Gaygurke2 жыл бұрын

    So if my sigmas are 1 that means my transpose is my ingular value decomposition

  • @youtubercocuq
    @youtubercocuq3 жыл бұрын

    I don't understand why we don't have two non zero elements in the scaling matrix sigma.

  • @phamtinkt88
    @phamtinkt882 жыл бұрын

    great video, appreciate your work, only 1 comment, could you speak more clearly. I am not a native speaker, I had a hard time follow your lecture as your words stick together

  • @categorygrp
    @categorygrp9 ай бұрын

    wish there was a way to make the voice in videos less... wet... makes it hard to listen to for some people

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