kai

Programming Machine Learning:

Programming Machine Learning
From Coding to Deep Learning
German edition

Chapter 11
Training the network
Page 191

def back(X, Y, y_hat, w2, h):
w2_gradient = np.matmul(prepend_bias(h).T, y_hat - Y) / X.shape[0]

 a_gradient = np.matmul(y_hat - Y, w2[1:].T) * sigmoid_gradient(h)
 w1_gradient = np.matmul(prepend_bias(X).T, a_gradient) / X.shape[0]

 return (w1_gradient, w2_gradient)

Hi Paolo,
can you explain me how to come to the decision to multiply this expression:
np.matmul(y_hat - Y, w2[1:].T) * sigmoid_gradient(h)
element by element?

Sincerely,
Kai

4 comments

#question /book-programming-machine-learning

1 553 4

2023-10-03 20:36:18 UTC

Most Liked

kai

As I understand it, there is no recipe to derive compositions of functions, whose inputs are matrices, according to them, as it is the case with a scalar.

Thank you for giving me an answer that helped my understanding anyway.

I am fascinated by mathematics and its power. But to be able to see its beauty, it requires a lot of time. That is why I asked such a question.

Your book was recommended to me and declared very worthwhile, which I can confirm 100%. It is my introduction to ML. Thank you for it!

Translated with DeepL Translate: The world's most accurate translator (free version)

Post #5

Where Next?

View thread on forum

View Programming Machine Learning's book portal

Post errata for this book

Post a suggestion for this book

Post a question about this book

Post a review about this book

question

Home PragProg Customers

#question /book-programming-machine-learning

1 553 4

Last post

Popular Pragmatic Bookshelf topics

PragProg Customers

Distributed Services With Go - Agent_test.go error line 77

This test is broken right out of the box… — FAIL: TestAgent (7.82s) agent_test.go:77: Error Trace: agent_test.go:77 agent_test.go:...

#errata /book-distributed-services-with-go

4 1559 7

2020-06-26 06:50:51 UTC

New

PragProg Customers

Python Testing with pytest - Chapter 5 example c AttributeError: 'module' object has no attribute 'config'

Running the examples in chapter 5 c under pytest 5.4.1 causes an AttributeError: ‘module’ object has no attribute ‘config’. In particula...

#errata /book-python-testing-with-pytest

5 3582 1

2020-07-14 20:43:55 UTC

New

PragProg Customers

The Ray Tracer Challenge: various errata

The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...

#errata /book-the-ray-tracer-challenge

4 2434 3

2021-05-25 09:44:21 UTC

New

PragProg Customers

Hands-on Rust: question about get_component

Title: Hands-on Rust: question about get_component (page 295) (feel free to respond. “You dug you’re own hole… good luck”) I have somet...

#question /book-hands-on-rust

1 1167 5

2021-02-01 15:17:34 UTC

New

PragProg Customers

Modern Front-End Development for Rails: B7 no main folder in the source code (page xv)

On the page xv there is an instruction to run bin/setup from the main folder. I downloaded the source code today (12/03/21) and can’t see...

#errata /book-modern-front-end-development-for-rails

2 1452 11

2022-03-08 17:27:57 UTC

New

PragProg Customers

Programming Phoenix LiveView: errata and remarks Version B2.0

The generated iex result below should list products instead of product for the metadata. (page 67) iex> product = %Product{} %Pento....

#errata /book-programming-phoenix-liveview

0 1800 20

2021-03-23 10:33:03 UTC

New

PragProg Customers

Web Development with Clojure, Third Edition (vB17.0): create table syntax invalid

Title: Web Development with Clojure, Third Edition, vB17.0 (p9) The create table guestbook syntax suggested doesn’t seem to be accepted ...

#errata /book-web-development-with-clojure-third-edition

0 1835 1

2021-08-13 23:56:52 UTC

New

PragProg Customers

Python Testing with pytest, Second Edition: cards pip install error (page 12)

#book-python-testing-with-pytest-second-edition Hi. Thanks for writing the book. I am just learning so this might just of been an issue ...

#errata /book-python-testing-with-pytest-second-edition

4 1191 3

2021-07-03 13:40:39 UTC

New

PragProg Customers

Powerful Command-Line Applications in Go: Exercise Solutions (many pages)

Is there any place where we can discuss the solutions to some of the exercises? I can figure most of them out, but am having trouble with...

#question /book-powerful-command-line-applications-in-go

17 1396 9

2022-02-09 15:00:31 UTC

New

PragProg Customers

Hands-on Rust: How do I debug a call chain in Rust?

When running the program in chapter 8, “Implementing Combat”, the printout Health before attack was never printed so I assumed something ...

#question /book-hands-on-rust

2 1034 2

2022-07-14 12:23:33 UTC

New

Other popular topics

General Dev>Hardware

Which keyboard do you have?

If it’s a mechanical keyboard, which switches do you have? Would you recommend it? Why? What will your next keyboard be? Pics always w...

#hardware /keyboards #sticky #mechanical-keyboards

144 9115 50

2021-01-07 23:58:36 UTC

New

General Dev>Dev Chat

Best chairs for developers?

What chair do you have while working… and why? Is there a ‘best’ type of chair or working position for developers?

#workspace #opinions

74 5463 41

2022-12-31 03:22:23 UTC

New

General Dev>Dev Chat

Which language or framework do you want to learn next?

Curious to know which languages and frameworks you’re all thinking about learning next :upside_down_face: Perhaps if there’s enough peop...

#community #learning

243 6639 97

2025-12-01 07:17:12 UTC

New

General Dev>Hardware

Poll: Which keyboard layout do you use?

poll poll Be sure to check out @Dusty’s article posted here: An Introduction to Alternative Keyboard Layouts It’s one of the best write-...

colemakmods.github.io

#polls /keyboards

10 6048 11

2020-10-31 23:12:33 UTC

New

General Dev>Code Editors

Dendron: a personal knowledge management tool on top of VSCode

/vscode #visual-studio-code

30 7372 9

2021-05-05 12:15:29 UTC

New

General Dev>Hardware

Planck vs Preonic vs Subatomic (Keyboards)

I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me. I think the Planck and the Preonic (o...

/keyboards #mechanical-keyboards #ortholinear #planck #preonic

105 17596 47

2021-05-28 21:32:35 UTC

New

Backend>Chat

Rails console using 100% CPU in dev (fix)

If you are experiencing Rails console using 100% CPU on your dev machine, then updating your development and test gems might fix the issu...

/ruby /rails

3 4188 3

2021-02-04 07:08:45 UTC

New

General Dev>Dev Chat

The V Programming Language

The V Programming Language Simple language for building maintainable programs V is already mentioned couple of times in the forum, but I...

#programminguages /v

21 13874 7

2021-04-12 15:13:42 UTC

New

Community>In The Spotlight

Spotlight: Erin Dees (Author) Interview and AMA!

Author Spotlight Erin Dees @undees Welcome to our new author spotlight! We had the pleasure of chatting with Erin Dees, co-author of ...

#author-spotlight /ruby /rails /book-effective-testing-with-rspec-3 /book-seven-more-languages-in-seven-weeks /book-cucumber-recipes #rspec

24 4247 11

2023-03-27 15:52:01 UTC

New

General Dev>In The News

Review of Linux on Minisforum V3 AMD Ryzen Tablet

A Brief Review of the Minisforum V3 AMD Tablet. Update: I have created an awesome-minisforum-v3 GitHub repository to list information fo...

mudkip.me

#linux #review #amd

0 4635 0

2024-06-24 02:26:38 UTC

New

Programming Machine Learning:

kai

Programming Machine Learning:

Most Liked

kai

Where Next?

Popular Pragmatic Bookshelf topics

Distributed Services With Go - Agent_test.go error line 77