Building a neural network FROM SCRATCH (no Tensorflow/Pytorch, just numpy & math)

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Kaggle notebook with all the code: www.kaggle.com/wwsalmon/simpl...
Blog article with more/clearer math explanation: www.samsonzhang.com/2020/11/2...

Пікірлер: 1 200

  • @victorafonso4534
    @victorafonso4534 Жыл бұрын

    Making a neural network from scratch is easy, what I really want to see is how to make a neural network ON scratch.

  • @d3vitron779

    @d3vitron779

    Жыл бұрын

    Make the scratch cat sentient challenge (gone wrong) (humanity destroyed)

  • @theRPGmaster

    @theRPGmaster

    Жыл бұрын

    Just create a python interpreter in Scratch, easy

  • @Despatra

    @Despatra

    Жыл бұрын

    Ok

  • @v037_

    @v037_

    Жыл бұрын

    Lmao, understimated comment, but perfect one

  • @BurNJoE

    @BurNJoE

    Жыл бұрын

    lol

  • @you_just
    @you_just Жыл бұрын

    i like how numpy has become so ingrained in python that it's basically considered vanilla python at this point

  • @nathanwycoff4627

    @nathanwycoff4627

    Жыл бұрын

    interestingly much of that functionality is built into other languages used by the ml community such as R, matlab and julia.

  • @mattrochford6783

    @mattrochford6783

    Жыл бұрын

    @@nathanwycoff4627 matrices and linear algebra are really useful for math and engineering less so for general programming. Different languages focusing on different usability concerns quite interesting.

  • @machineman8920

    @machineman8920

    Жыл бұрын

    @@mattrochford6783 stop coping julia is just a better language

  • @HilbertXVI

    @HilbertXVI

    Жыл бұрын

    @@machineman8920 ???

  • @thebluriam

    @thebluriam

    Жыл бұрын

    I don't like it. I wish people stopped being overly-lazy with Numpy and just wrote their own libraries so they'd understand what they are actually doing. No, scratch that, if they can't accomplish the same thing using only Assembly, they're a total noob, should put down their keyboard, and get an MBA instead...

  • @alperengul8654
    @alperengul86543 жыл бұрын

    If you make more deep learning videos with numpy and math(without any framework) just like in this video, it would be great for begginers to learn basics!!! Do you think to keep continue??

  • @cemsalta

    @cemsalta

    3 жыл бұрын

    Merhaba Eren!

  • @kanui3618

    @kanui3618

    3 жыл бұрын

    upp!

  • @anishojha1020

    @anishojha1020

    3 жыл бұрын

    Hey guys, a reply would be highly appreciated. I want to plot the cost vs the number of iterations but I am not able to figure which parameter to plot ? I am a beginner and I would really appreciate the help. Thank you

  • @KHM95

    @KHM95

    2 жыл бұрын

    Here's a course you'll need. Face Mask Detection Using Deep Learning and Neural Networks. It's paid but it's worth it. khadymschool.thinkific.com/courses/data-science-hands-on-covid-19-face-mask-detection-cnn-open-cv

  • @whannabi

    @whannabi

    2 жыл бұрын

    @@anishojha1020 you're probably not a beginner anymore so I hope you found your answer! Unfortunately, youtube comment section isn't a forum and a lot of people disable notifications(including me) so an actual forum although people are sometimes really rude and condescending, is your best bet for future questions.

  • @khoa4k266
    @khoa4k2665 ай бұрын

    I watched this video when I was studying in grade 11. Had no clue what he was talking about but I tried to understand as much as possible. Now I watch it again as a university student, it is so satisfying to understand everything now.

  • @viCuber

    @viCuber

    3 ай бұрын

    Hope that will happen to me to

  • @CR33D404

    @CR33D404

    3 ай бұрын

    @@viCuber same LOL

  • @viCuber

    @viCuber

    3 ай бұрын

    @@CR33D404 lmao

  • @codevacaphe3763

    @codevacaphe3763

    2 ай бұрын

    It happens to me several time. Sometime you just stumble on a knowledge and can't understand a single thing about it then suddenly 1 or 2 years later you completely understand it without any try.

  • @nachoyawn

    @nachoyawn

    2 ай бұрын

    same

  • @jumpierwolf
    @jumpierwolf Жыл бұрын

    Took a Machine Learning course in university and this is what we did the whole semester in Matlab. Tensorflow was introduced right at the end for the final project.

  • @gasun1274

    @gasun1274

    Жыл бұрын

    sounds amazing

  • @marshmellominiapple

    @marshmellominiapple

    Жыл бұрын

    oh hell yea matlab

  • @ElectrostatiCrow

    @ElectrostatiCrow

    Жыл бұрын

    ​@@marshmellominiapple oh he'll yeah methlab

  • @dumbfate

    @dumbfate

    9 ай бұрын

    @@ElectrostatiCrow LET HIM COOK

  • @PluetoeInc.

    @PluetoeInc.

    Ай бұрын

    @@dumbfate no you let him cook

  • @MegaJesusini
    @MegaJesusini Жыл бұрын

    My man really explained how a back propagated neural network works from scratch in 10 minutes

  • @tecknowledger
    @tecknowledger3 жыл бұрын

    This video is one of the best descriptions of neural networks written in only Numpy and Python I've ever seen. Thanks

  • @anishojha1020

    @anishojha1020

    3 жыл бұрын

    Hey guys, a reply would be highly appreciated. I want to plot the cost vs the number of iterations but I am not able to figure which parameter to plot ? I am a beginner and I would really appreciate the help. Thank you

  • @tecknowledger

    @tecknowledger

    3 жыл бұрын

    @@anishojha1020 Hi, try posting comment again in regular comments part, so more people see it. This is only a sub-comment.

  • @waterspray5743

    @waterspray5743

    2 жыл бұрын

    @@KHM95 Hi, are you a bot?

  • @KHM95

    @KHM95

    2 жыл бұрын

    @@waterspray5743 No man, I am not.

  • @ME0WMERE

    @ME0WMERE

    2 жыл бұрын

    I advise looking at sendex's 'Neural Network from scratch' series

  • @TimeRoot
    @TimeRoot Жыл бұрын

    00:51 Problem statement 01:18 Math explanation 11:18 Coding it up 27:43 Result's

  • @omgcyanide4642

    @omgcyanide4642

    Жыл бұрын

    Thank you

  • @Zetzumarshen

    @Zetzumarshen

    Жыл бұрын

    Thank you

  • @Dejwv_

    @Dejwv_

    Жыл бұрын

    Thank you

  • @Salien1999

    @Salien1999

    Жыл бұрын

    Thank you

  • @SandSeppel

    @SandSeppel

    Жыл бұрын

    Thank you

  • @Mutual_Information
    @Mutual_Information Жыл бұрын

    Just discovered this channel. Very cool stuff. Much respect for doing something challenging like this.

  • @hcmcnae
    @hcmcnae Жыл бұрын

    I'm so glad you actually went in depth with the math explanation. So often people will just explain surface layer and then "alright lets jump into the code".

  • @luisbq8045
    @luisbq804510 ай бұрын

    This is pure gold, MSc in Data Science and Artificial Intelligence, no professor ever gave me the answer to "what is the code inside the libraries we use", until I found you. Thank you

  • @rushisy

    @rushisy

    10 ай бұрын

    thats sad

  • @stanislavlia

    @stanislavlia

    7 ай бұрын

    I don't want to sound too catchy and annoying but the NN's in Tensorflow and PyTorch are not actually implemented like this. They don't store functions to compute gradients for every single option rather they use AutoGradient which does all backpropogation job. I would highly recommend to watch Andrej Karpathy's tutorial on micrograd (mini AutoGradient which you will implement)

  • @michaelpieters1844

    @michaelpieters1844

    2 ай бұрын

    I got a master in physics and statistics but I do know how to code a lot of "machine learning" techniques from scratch. Yet human resources look at my degree and think I am incapable, so they rather hire master in AI. I can also code CFD, SPH and FEA from scratch but HR say I am dumber than engineer who just uses third party software (ansys).

  • @suscactus420

    @suscactus420

    Ай бұрын

    @@michaelpieters1844 welcome to recruitment in 2024... you need to feed the recruiters what they want to hear, so that you can then get to the guy who you actually want to talk to about your stuff.

  • @LydellAaron
    @LydellAaron Жыл бұрын

    Just your intro alone in your motivations was so capturing. You laid out everything so clearly, including creating those row and column matrices in the early steps. Thank you.

  • @darrellrayford3817
    @darrellrayford3817 Жыл бұрын

    This was a really good video. I’ve never build a neural network but it was interesting seeing how the fundamentals add up to build something a little more complexed.

  • @lbb2rfarangkiinok
    @lbb2rfarangkiinok Жыл бұрын

    This was really neat. The math explanation was frustrating the first time around but really made sense after working through the code. Thanks for sharing.

  • @randyscorner9434
    @randyscorner94342 ай бұрын

    Excellent tutorial and example. Reveals the magic that most don't know about NNs and I love how you go about it.

  • @minjunkevink
    @minjunkevink2 жыл бұрын

    Amazing. Needed to see the low end and finally found it. Thank you for the amazing video!

  • @Bobbleheads56
    @Bobbleheads56 Жыл бұрын

    I need to come back to this after learning some more preliminaries but you are a very natural teacher and good at presenting. Keep it up 👍

  • @traviss7740
    @traviss7740 Жыл бұрын

    I've never heard any of this explained before. After watching this once, I understand the mathematics behind neural networks and why the functions are used. Great job with the explanation here. Many thanks.

  • @joschkazimdars
    @joschkazimdars2 жыл бұрын

    It feels like it took me months to understand programming feedforward neural networks but I finally understand it. Thanks for the video.

  • @Hex...
    @Hex... Жыл бұрын

    This was interesting, it certainly made neural networks far more approachable to me as someone who's never needed to/been inclined to try making one, but encounters them frequently by being involved in STEM. Your explanations coupled with my familiarity with numpy as opposed to dedicated libraries for neural networks really helped - thanks!

  • @faris.abuali
    @faris.abuali Жыл бұрын

    Thank you so much Mr. Samson!! This was so informative and enlightening

  • @omlachake2551
    @omlachake25512 жыл бұрын

    this type of learning is honestly the best, i implemented k means clustering by myself in c (pretty easy stuff but still) , and i can never forget it now, makes me happy that i can do stuff too

  • @Emily-fm7pt

    @Emily-fm7pt

    Жыл бұрын

    When I was in high-school algebra I programmed an algebra calculator to do my homework for me, and for some reason I never actually needed it. Programming something really is a great way of learning it, even if it does take significantly longer than just some p-sets or flashcards.

  • @OT-tn7ci

    @OT-tn7ci

    Жыл бұрын

    @@Emily-fm7pt dude are you serious ??? SAME SAME lmao

  • @auronusben4567

    @auronusben4567

    11 ай бұрын

    I remember when I tried to implement a decision tree on paper !! With a very small data dimensions (maybe 5x6 dim? Can't remember). I spent all the night doing the math but after 5-6 hours I realized I made a mistake in an iteration 😂😂 that's when I realized that we're lucky to have computers to help do it because a human mind can't build completely without doing mistakes in the process (can't stay focus for long time)... I also remember when I implemented a PCA from scratch on excel ( still have the Excel 😂)...😮

  • @mauricioledon4498
    @mauricioledon4498 Жыл бұрын

    You sir, are my hero. You are the first person to actually explain this properly to me. Thank you so much for that.

  • @momol.9892
    @momol.989219 күн бұрын

    Just learned basics around the neural networks and saw this video. So satisfied to all the math formulas are laid out clearly in numpy and real-world coding and training neural network with back propagation. It really helps beginners like me. Thank you so much!

  • @jeandy4495
    @jeandy4495 Жыл бұрын

    Super cool! Would also recommend the series from The Coding Train about creating a neural network from scratch, going a little more into the details of math and what is a perceptron and so.

  • @albertolemosduran5685
    @albertolemosduran5685 Жыл бұрын

    Most of the videos are titled “how to create a blabla” when they’re actually teaching how to use… so I really appreciate your video! This really contributes to knowledge 🥰

  • @anandptyagi5275
    @anandptyagi5275 Жыл бұрын

    After Andrew Ng's course, this is the first time I'm watching math functions, thanks buddy, it was a nice refresher for me.

  • @hocm2
    @hocm28 күн бұрын

    Maaan, I am so happy you made this video. I was looking for somebody to train the Neural Network from scratch. I will go through it several times to get into the subject. Your English is excellent! Many, many thanks!

  • @chessprogramming591
    @chessprogramming591 Жыл бұрын

    Thank you for your time and effort, Samson, this tutorial is a treasure.

  • @juliocardoza6066
    @juliocardoza6066 Жыл бұрын

    Samson, Keep doing this kind of videos please!! Very intelligent and understandable video

  • @waynesletcher7470
    @waynesletcher74705 ай бұрын

    Love your sense of humor! Brought the video to life, thanks! You are appreciated!

  • @jasonavina8135
    @jasonavina8135 Жыл бұрын

    In case any beginners to ML came here wondering why they are really confused, this video isn't really for beginners and he doesn't really explain that. Its "from scratch" in the sense of not using any prebuilt models in the code. Its a good explanation for people who are already familiar with neural networks, prebuilt layers, loss functions, etc. not for people starting their understanding "from scratch."

  • @OT-tn7ci

    @OT-tn7ci

    Жыл бұрын

    actually im new to ML, (2-3 months in) and this helped me understand a lot, i am implementing it on my own now, without even using numpy so i can code out stuff like transpose on my own and learn more. Random is tricky tho lol

  • @robertknopf6207
    @robertknopf62073 жыл бұрын

    Another thing that would be helpful for those of us that want to copy what you did and experiment with it is to have all the code together instead of separated as it is using Kaggle - this way you can put in some comments with the code explaining the different features. Again, very good video.

  • @RonClabo
    @RonClabo3 жыл бұрын

    What an awesome video! Thank you for sharing this insightful walkthrough, it was really helpful in getting a better understanding of how neural nets works. Thank you!

  • @KHM95

    @KHM95

    2 жыл бұрын

    Here's a course you'll need. Face Mask Detection Using Deep Learning and Neural Networks. It's paid but it's worth it. khadymschool.thinkific.com/courses/data-science-hands-on-covid-19-face-mask-detection-cnn-open-cv

  • @peterweicker77
    @peterweicker775 ай бұрын

    This is great. Built a backprop in C thirty years ago to solve the same problem. Just for a goof. It worked well before I finished debugging. These things are awesome and now I want to take another look. Thanks for posting this.

  • @aureliencobb199
    @aureliencobb199 Жыл бұрын

    Brilliant. Kind of the Hello World of neural nets. It shed a lot of light for me on how back propagation works.

  • @KSATica
    @KSATica Жыл бұрын

    You should continue making video similar to this maybe something a training course for machine learning and reinforcement learning AI. You have a real talent for explaining it in the best way possible then from what most videos I’d watched. 👍

  • @FreakyStyleytobby
    @FreakyStyleytobby Жыл бұрын

    Man this video is a masterpiece. I learned a lot and I love your thorough, calm style. Please keep doing similar content!! Best wishes

  • @ItsNaberius
    @ItsNaberiusАй бұрын

    Really excellent breakdown of a Neural Network, especially the math explanation in the beginning. I also want to say how much I appreciate you leaving in your first attempt at coding it and the mistakes you made. Coding is hard, and spending an hour debugging your code just because of one little number is so real. Great video

  • @deananderson8186
    @deananderson8186 Жыл бұрын

    I loved this video! Cool stuff. I implemented a tfidf clustering algorithm myself, very satisfying to see it all working

  • @AAAJ27
    @AAAJ27 Жыл бұрын

    Samson, this was such a great walk through. Just wanted to say that if you ever made other videos recreating machine learning models from scratch, I'd 100% watch them. In any case, hope all is good and thanks for this great content :)

  • @GrahamEckel
    @GrahamEckel Жыл бұрын

    Better lecture and example for understanding and building NN than any in my math and stats MSc

  • @straightup7up
    @straightup7up5 ай бұрын

    Samson, we need more videos like this from you. Great content, more visuals would be nice, too 🙂

  • @ricardogomes9528
    @ricardogomes9528 Жыл бұрын

    Awesome fundamental class on neural networks equations. Bravo!

  • @SnackPack913
    @SnackPack913 Жыл бұрын

    I’m always too intimidated to try some of these things. But seeing your process makes it really seem feasible. Need to brush up on my linear algebra again tho 😆

  • @Crayphor
    @Crayphor Жыл бұрын

    It's worth noting that softmax IS actually very similar to sigmoid. But it essentially does a sigmoid over multiple classes.

  • @gnorts_mr_alien
    @gnorts_mr_alien Жыл бұрын

    This is the first ASMR NN video that I have ever seen. Well done.

  • @kurtameyer
    @kurtameyer3 ай бұрын

    Thank you. I'm doing this in class right now and your explanations were super helpful!

  • @solleo9
    @solleo9 Жыл бұрын

    What an impressive speed run! Just nitpicking: 15:45 `rand` is for a uniform dist U(0,1) and `randn` is for the standard normal distribution N(0,1), therefore unbounded, not U(-0.5, 0.5)

  • @FireNLightnin
    @FireNLightnin Жыл бұрын

    Great video! I did the same thing in python about a year ago, but I didn’t like relying on numpy so much. Your video gave me the motivation to write both a matrix manipulator and neural network from scratch in Java

  • @TheJackTheLion

    @TheJackTheLion

    10 ай бұрын

    I did it in assembly, easy

  • @letticonionepic
    @letticonionepic9 ай бұрын

    I know the Maths and Programming behind it and listening this guy doing all that on his own is pure respect from my side.

  • @drgatsis
    @drgatsis Жыл бұрын

    Thanks for lovely video Samson. I'm a prof and love seeing this kind of content. I'll definitely share with students

  • @notyou4122
    @notyou4122 Жыл бұрын

    Musician, filmmaker, data scientist, and etc. bro maxed out on skill trees. 😂

  • @123arskas
    @123arskas Жыл бұрын

    Just 1 minute in the video and I can easily tell that you're gonna own a multi-billion company within a few years. You've got the IQ, the voice, the clarity, the confidence, and the right personality. Best of luck Mr. Zhang

  • @llewsub
    @llewsub8 ай бұрын

    Most tutorials I watch online about ML, you can just tell that the instructor doens't know whats happening. They've just memorized libraries and tensorflow syntax, and I don't want that to be me! This is exactly what i've been looking for! THANK YOU!!!

  • @jasonkim1642
    @jasonkim1642 Жыл бұрын

    Great video! It's really solid in foundation! I will definitely recommend this to those just like to use framework and library without understanding

  • @sharmakartikeya
    @sharmakartikeya2 жыл бұрын

    Bro, that is exactly how I study! I found out your channel and I am so glad I did. Instantly subscribed! I see you have learnt from Andrew Ng

  • @rishikeshkanabar4650

    @rishikeshkanabar4650

    2 жыл бұрын

    yeah the notations reminded me of Andrew Ng

  • @kumaranp8764

    @kumaranp8764

    2 жыл бұрын

    @@rishikeshkanabar4650 usage of the word called "intuition" reminds me of him saying ..."to get a better intuition" in his lectures

  • @David-ip2sd
    @David-ip2sd Жыл бұрын

    Hi! I did a recreation of your code with more hidden layers and noticed what I think is a bug in the db calculation. Changing it to db = 1 / m * np.sum(dZ, axis=1).reshape(-1, 1) was able to get me better results. I think the old db = 1 / m * np.sum(dZ) sums the entire dZ to one float. Very good video though!

  • @Hyngvi

    @Hyngvi

    Жыл бұрын

    noticed the same thing. The way it was implemented here returns db to a float and thus b will always be "similar" to the random initialization, only shifted up/down by a constant.

  • @mattlange00

    @mattlange00

    6 ай бұрын

    Hey, I know you posted this a while ago, but I noticed the same thing and saw your comment. I am still not sure how to solve this, dZ is still a 1D array (1 by 10) so in your solution, what does axis=1 do? won't .sum*() just turn the 1D array into a scalar regardless, and then you are back with the same problem of updating all your biases the same way?

  • @mattlange00

    @mattlange00

    6 ай бұрын

    Actually, nevermind, dZ is 10 by m so this does make sense

  • @gpeschke

    @gpeschke

    4 ай бұрын

    Numpy requires some strange things when you have only 1 dimension: Verfied that without this change the final biases weights aren't being updated. With it, training works better. Didn't verify the details of David's solution, just that it was needed, and that it seemed to work. def backward_prop(Z1, A1, Z2, A2, W1, W2, X, Y): one_hot_Y = one_hot(Y) dZ2 = A2 - one_hot_Y dW2 = 1 / m * dZ2.dot(A1.T) db2 = 1 / m * np.sum(dZ2, axis=1).reshape(-1, 1) dZ1 = W2.T.dot(dZ2) * ReLU_deriv(Z1) dW1 = 1 / m * dZ1.dot(X.T) db1 = 1 / m * np.sum(dZ1, axis=1).reshape(-1, 1) return dW1, db1, dW2, db2

  • @danielmyers76

    @danielmyers76

    17 күн бұрын

    I see the same. Also, either this is old enough that something has changed in Python or numpy, or he hasn’t included other things as well. Using his code line for line and the same data set, I get a divide by zero error on the softmax function.

  • @arksodyssey
    @arksodyssey3 ай бұрын

    This solved a lot of doubts and brought up mu confidence levels to deep dive into AI/ML. Thanks for the explanation.

  • @luizarnoldchavezburgos3638
    @luizarnoldchavezburgos3638 Жыл бұрын

    Keep doing it man, I am from Perú and the information that your are giving is the important I have heared about

  • @tommyhuffman7499
    @tommyhuffman7499 Жыл бұрын

    It's a shame it isn't taught this way in courses. Excellent video!

  • @work9466
    @work94662 жыл бұрын

    I actually did this exact same thing for my German a level project. Same database. :D good times

  • @bf300
    @bf300 Жыл бұрын

    Really cool video Samson! Great stuff!

  • @edisonbekaj863
    @edisonbekaj863 Жыл бұрын

    Samson Zhang is the BEST Cinematographer, editor, musician& tech geek in the WORLD

  • @f.osborn1579
    @f.osborn1579 Жыл бұрын

    Haven’t finished video yet, but this looks like the missing piece of my experience learning about neural networks at a high level…I probably lacked the linear algebra skills I have now though. Whoa! This could be incredibly exciting! I can’t wait!

  • @mrgenetics4063

    @mrgenetics4063

    Жыл бұрын

    Nobody cares what you have to say

  • @kiaruna
    @kiaruna Жыл бұрын

    Could you please do more tutorials ? This is such a great video

  • @cgswjs
    @cgswjs Жыл бұрын

    This is exactly what I've been looking for!Thank you.

  • @DiAMONDBACK85
    @DiAMONDBACK858 ай бұрын

    Hi Samson! I'm a developer and trying to learn the basics of ML. Much of the beginner stuff I see is using pre-trained models and frameworks which might be convenient to get things going. However, for me this is something completely new and I really what to understand what happens behind the scenes. Thank you for posting this! /Kevin from Sweden

  • @paultvshow

    @paultvshow

    3 ай бұрын

    ⁠Exactly!

  • @carnap355

    @carnap355

    3 ай бұрын

    try jeremy howard part2 of 2022 courses

  • @kamaldani1686
    @kamaldani1686Ай бұрын

    Understood nothing but wow

  • @youri655
    @youri655 Жыл бұрын

    Very impressive! Great commentary/explanation as well

  • @williamzhang6955
    @williamzhang6955 Жыл бұрын

    That is very neat and captures the fundamental ideas of neural nets! great job

  • @mercedeszkistoth5367
    @mercedeszkistoth5367 Жыл бұрын

    There is one thing I do not understand. Because the derivation and chain rule stuff, shouldn't the derivative of the softmax activation function also be included somewhere?

  • @dcrespin
    @dcrespin Жыл бұрын

    An excellent nice video with abundant mathematical insight. It may be worth to note that instead of partial derivatives one can work with derivatives as the linear transformations they really are, and also looking at the networks in a more structured manner thus making clear how the basic ideas of BPP apply to much more general cases. Several steps are involved. 1.- More general processing units. Any continuously differentiable function of inputs and weights will do; these inputs and weights can belong, beyond Euclidean spaces, to any Hilbert space. Derivatives are linear transformations and the derivative of a neural processing unit is the direct sum of its partial derivatives with respect to the inputs and with respect to the weights; this is a linear transformation expressed as the sum of its restrictions to a pair of complementary subspaces. 2.- More general layers (any number of units). Single unit layers can create a bottleneck that renders the whole network useless. Putting together several units in a unique layer is equivalent to taking their product (as functions, in the sense of set theory). The layers are functions of the of inputs and of the weights of the totality of the units. The derivative of a layer is then the product of the derivatives of the units; this is a product of linear transformations. 3.- Networks with any number of layers. A network is the composition (as functions, and in the set theoretical sense) of its layers. By the chain rule the derivative of the network is the composition of the derivatives of the layers; this is a composition of linear transformations. 4.- Quadratic error of a function. ... --- Since this comment is becoming too long I will stop here. The point is that a very general viewpoint clarifies many aspects of BPP. If you are interested in the full story and have some familiarity with Hilbert spaces please google for papers dealing with backpropagation in Hilbert spaces. A related article with matrix formulas for backpropagation on semilinear networks is also available. For a glimpse into a completely new deep learning algorithm which is orders of magnitude more efficient, controllable and faster than BPP search in this platform for a video about deep learning without backpropagation; in its description there are links to a demo software. The new algorithm is based on the following very general and powerful result (google it): Polyhedrons and perceptrons are functionally equivalent. For the elementary conceptual basis of NNs see the article Neural Network Formalism. Daniel Crespin

  • @aaliyahiam4286
    @aaliyahiam4286 Жыл бұрын

    this man appeared, released an absolute banger of a programming video, and proceeded to never posted any cs content again. sigma mentality tbh

  • @Felix14325
    @Felix14325 Жыл бұрын

    Amazing video for beginners to gain an insight in how neural networks work. You just have to have programmed a simple neural net from scratch once to have a good basic understanding.

  • @ricardo5875
    @ricardo58752 жыл бұрын

    This is a great way to teach ANN - congrats. However, I would like to suggest you to not worry too much about the time to finish the implementation. Double-checking all steps will avoid coding errors.

  • @themoonlight1922
    @themoonlight19222 жыл бұрын

    Hi, i found this video very helpful for beginners. Could you please tell how you came up the equations of dz,dw and db? That would be really helpful as well

  • @aryamankukal1056

    @aryamankukal1056

    Жыл бұрын

    watch andrew ng he copied every single equation from his course

  • @Nanakwaku309

    @Nanakwaku309

    Жыл бұрын

    @@aryamankukal1056 I wouldn’t say he copied every equation. These equations are taught in all ML/AI courses and it is just mathematics

  • @aryamankukal1056

    @aryamankukal1056

    Жыл бұрын

    @@Nanakwaku309 andrew's notation is a very specific and if u watch carefully he uses all of the same conventions

  • @iggzistentialism8458
    @iggzistentialism8458 Жыл бұрын

    This was really useful to me, and incredibly well explained. Thank you.

  • @nextcomputerparts
    @nextcomputerparts11 ай бұрын

    A great introduction to neural networks is Parallel Distributed Programming by Rumelhart and McLelland from about 1986. They do something similar and give a lot of additional background.

  • @Kaetemi
    @Kaetemi7 ай бұрын

    Helpful, thanks. Made my own from scratch in bare C++. From image to 32 to 16 to 10 outputs, using leaky ReLU. 96% accuracy on the test set. 🥳

  • @cbeezy4733
    @cbeezy4733 Жыл бұрын

    Perhaps I overcomplicated matters compared to your approach when I did this a couple of years ago, but like you, I wanted to program it "from scratch". My language of choice: java. I actually simulated "neurons" which were a class that stored its activation data value, and its connections to the next layer, so that it "looked" like a K_m,n graph, and the connection was an array which stored the biases along each "synapse" so to speak. Then when the hidden layers activated, I had each neuron simply sum the outputs from each synapse connecting to it from the previous layer, which was just the product of its activation value and its bias, then sigmoided this to get its own activation value. Note that while each neuron's activation was only in (-1,1), I let the biases be free parameters. When I programmed the backprop algo, I did the gradient descent the same as you, but effectively set that alpha parameter to one. It didn't occur to me to mess with that. Starting the network out with random parameters, then training it on randomly chosen sets of 10,000 images five or six times seemed to work pretty well. I saw 93% accuracy on the test data. And just for fun, I put the network on a discord bot so my friends could feed it images of the same size and see its guess. Two interesting results came out. The network fails on inverted colors: i.e., drawing white on black using MS paint or something wouldn't get reliable predictions. Secondly, using MS paint to give it new data did work, but at a much lower rate. Our best guess for why this happened was due to the sharpness of the lines between the number and backgrounds.

  • @derpythecate6842
    @derpythecate68422 ай бұрын

    The most sadistic thing I've made for a school project was a multi layer perceptron in C. No stdlibs either. Just raw hard math, all functions were approximated where possible e.g sigmoid, multiplication since it wasn't available. The only part I couldn't make was to generate randomness in initial weights which is important to ensure neurons train assymetrically. It was all so it would run on a custom RISC V processor (which the multiply, or M extension was sometimes unavailable). My proudest and most depressing creation.

  • @sanglar3623
    @sanglar3623 Жыл бұрын

    The yt algorithm only recommends me this now, 1 year after i've encountered a similar discontent with neural network tutorials. Still very interresting to see how someone else does it. I did give myself a bit of help by using a library called Eigen for the matrixes calculations. Very well done nice video

  • @GiacomoMiola
    @GiacomoMiola Жыл бұрын

    It's a MLP, you easily computed the backpropagation step in closed form, but I wonder how those famous frameworks can compute any network's partial-derivatives tensors automatically

  • @elliott614

    @elliott614

    Жыл бұрын

    usually the partial derivatives in backpropagation are of functions specifically chosen to be convex and have nothing to do with the problem you are working on, but are just ones that work nicely for ML algos

  • @xuxusito
    @xuxusito3 жыл бұрын

    Very good video and explanation! Thanks 😊. I just would have liked it if you had explained the backprop a little more in depth. Like how the derivatives are calculated on each layer (chain rule etc.) But other than that one of the best nn videos

  • @KHM95

    @KHM95

    2 жыл бұрын

    Here's a course you'll need. Face Mask Detection Using Deep Learning and Neural Networks. It's paid but it's worth it. khadymschool.thinkific.com/courses/data-science-hands-on-covid-19-face-mask-detection-cnn-open-cv

  • @dbbyres
    @dbbyres4 ай бұрын

    Nicely done, Samson, thanks!

  • @quanduong8917
    @quanduong89173 жыл бұрын

    You can actually use momentum for gradient descent. The result is slightly better (I tried on your nn and it gets 91% accuracy) // I'm a beginner at ML so your video taught me a lot. Keep up your great work you're doing man. It's really cool.

  • @akainu3668

    @akainu3668

    3 жыл бұрын

    can you please send link of your code

  • @harisjaved1379
    @harisjaved1379 Жыл бұрын

    I agree with you. I also did this by scratch. It was a lot of fun! What’s the point of masters math degree if I am not going to use it lol. Nice work!

  • @Pk-tw6li

    @Pk-tw6li

    Жыл бұрын

    bro can you help i also wanna learn can you tell us resources which you use to learn this neural network

  • @juliopaniagua8723

    @juliopaniagua8723

    Жыл бұрын

    @@Pk-tw6li study some basic linear algebra, just with that you'll understand at least 85% of whats going on with the algorithm

  • @hayashii5837
    @hayashii5837Ай бұрын

    thank you for the knowledge Mr. Samsung

  • @jamescardenas837
    @jamescardenas837Ай бұрын

    i have no idea what your were really saying but at the same time i do because you explained how the math is used and implemented for the code. thank you !

  • @isreallealbertsanchez1156
    @isreallealbertsanchez11563 жыл бұрын

    Timestaps if you forgot 0:51 Problem Statement 1:18 Math Explanation 11:18 Coding It up 27:43 Results

  • @KHM95

    @KHM95

    2 жыл бұрын

    Here's a course you'll need. Face Mask Detection Using Deep Learning and Neural Networks. It's paid but it's worth it. khadymschool.thinkific.com/courses/data-science-hands-on-covid-19-face-mask-detection-cnn-open-cv

  • @Achrononmaster

    @Achrononmaster

    Жыл бұрын

    @18:07 is the time stamp where the other error was made, a2 = softmax(a1) which should be a2 = softmax(z2)

  • @Achrononmaster

    @Achrononmaster

    Жыл бұрын

    @23:30 you also see two errors, there is no axis argument for the np.sum(), the lines should be db2 = 1 / m * np.sum(dZ2) ... and ... db1 = 1 / m * np.sum(dZ1)

  • @Achrononmaster

    @Achrononmaster

    Жыл бұрын

    And @23:00 ReLU_deriv(z) should really be return np.array(zn > 0, dtype=float) if you are aiming for good typing practice.

  • @elivegba8186

    @elivegba8186

    Жыл бұрын

    I don't understand anything but wow

  • @danielniels22
    @danielniels223 жыл бұрын

    Hello, it's such a great tutorial. thank you very much. I think people who are over exited because of this AI-hyped should learn this basic, and see whether those people really fit in to this field 🤣🤣

  • @DungeonMasterpiece
    @DungeonMasterpiece Жыл бұрын

    I've been looking for this video for 6 years.

  • @a-balah
    @a-balah Жыл бұрын

    Great Video! Inspired me to build up my basics first and start from a low level perspective.

  • @Milorae
    @Milorae Жыл бұрын

    Everyone praises this video for being so helpful and I'm just sitting here understanding NOTHING. :D I feel so dumb! Maybe I should've stared with something even more basic having learned in a nutshell only print("hello world") so far. I will definitely go back and watch it all again in the future after I learn more. Thank you for the video, Samson. Cheers!

  • @xianzai_ad1928

    @xianzai_ad1928

    Жыл бұрын

    defintely pick up a book on algorithims and data structures first!

  • @ReBufff
    @ReBufff Жыл бұрын

    Now build one IN Scratch

  • @be7256

    @be7256

    Жыл бұрын

    been done actually

  • @carloscortes2391
    @carloscortes23915 ай бұрын

    I am going to do the same over the next two weeks , at the end I'm coming back to see any differences between our code, thanks for sharing :)

  • @amauta5
    @amauta5 Жыл бұрын

    Samson, thank you for this vid.

  • @nitinrohit1669
    @nitinrohit16692 жыл бұрын

    Hey, I found a flaw in your code and would be great if you answer it......The updation that you are doing for the bias' is not all needed as per your code because all the bias are changed by same factor hence it's still random( you have used a scalar to update the bias instead of a column vector)......I found the correct solution to it but getting an error. you should add the axis=1 in the sum function.

  • @lucasphillips2177

    @lucasphillips2177

    Жыл бұрын

    ya I encountered that, too and fixed it like you said.

  • @Ari-Matti.Rintala
    @Ari-Matti.Rintala Жыл бұрын

    Amazing stuff! Just wondering what value does the coding timer add to the video? I mean instead of correcting your mistakes with overlapping text you could have taken a little bit of time to review your code instead of rushing it through. But again, amazing content!

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