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

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

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

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

A Common-Sense Guide to Data Structures and Algorithms, Second Edition: erroneous extra space complexity (page400)

A Common-Sense Guide to Data Structures and Algorithms, Second Edition by Jay Wengrow @jaywengrow Hi, I have the paperback version of t...

#errata /book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition

4 1180 2

2021-07-27 21:37:42 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

Kotlin and Android Development featuring Jetpack: $kotlin_version ? (page 8)

I’m running Android Studio “Arctic Fox” 2020.3.1 Patch 2, and I’m embarrassed to admit that I only made it to page 8 before running into ...

#errata /book-kotlin-and-android-development-featuring-jetpack

0 1698 3

2021-09-03 21:44:18 UTC

New

PragProg Customers

Real-Time Phoenix: ProductChannelTest - undefined function describe/2 (pg 203)

Hi, I am getting an error I cannot figure out on my test. I have what I think is the exact code from the book, other than I changed “us...

#question /book-real-time-phoenix

0 1775 6

2022-02-16 19:15:15 UTC

New

PragProg Customers

Docker for Rails Developers - 'docker-machine' command deprecated (page 156)

Docker-Machine became part of the Docker Toolbox, which was deprecated in 2020, long after Docker Desktop supported Docker Engine nativel...

/book-docker-for-rails-developers #suggestion

0 896 0

2023-03-06 18:01:33 UTC

New

PragProg Customers

Kotlin and Android Development featuring Jetpack: Unique constraint error when running chapter 5 code changes

@mfazio23 I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game,...

/book-kotlin-and-android-development-featuring-jetpack

0 1180 10

2023-08-07 20:43:16 UTC

New

PragProg Customers

Bug with dx/build - how to workaround until fix is up

Hello faithful readers! If you have tried to follow along in the book, you are asked to start up the dev environment via dx/build and ar...

#errata /book-ruby-on-rails-background-jobs-with-sidekiq

3 1178 19

2024-01-23 22:22:16 UTC

New

Other popular topics

Backend>Learning Resources

Web Development with Clojure, Third Edition

Stop developing web apps with yesterday’s tools. Today, developers are increasingly adopting Clojure as a web-development platform. See f...

pragprog.com

#pragprog #web-development /clojure #published-book /book-web-development-with-clojure-third-edition

5 4584 1

2022-01-06 05:27:09 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>Code Editors

Onivim 2 Code Editor

Thanks to @foxtrottwist’s and @Tomas’s posts in this thread: Poll: Which code editor do you use? I bought Onivim! :nerd_face: https://on...

#code-editors /onivim /revery

88 6144 32

2023-05-15 07:32:26 UTC

New

Frontend>Learning Resources

Modern CSS with Tailwind

Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...

pragprog.com

#pragprog /tailwind #published-book /book-modern-css-with-tailwind

12 5813 4

2021-05-13 14:50:23 UTC

New

Backend>Chat

How to install Ruby 3 with ASDF

In case anyone else is wondering why Ruby 3 doesn’t show when you do asdf list-all ruby :man_facepalming: do this first: asdf plugin-upd...

/ruby #asdf

11 5961 4

2021-02-02 08:02:13 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: VM Brasseur (Author) Interview and AMA!

Author Spotlight: VM Brasseur @vmbrasseur We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...

#author-spotlight /book-forge-your-future-with-open-source

16 5051 11

2023-03-27 16:00:12 UTC

New

Community>In The Spotlight

Spotlight: Bruce Tate (Author) Interview and AMA!

Author Spotlight: Bruce Tate @redrapids Programming languages always emerge out of need, and if that’s not always true, they’re defin...

/elixir /ruby /phoenix /book-seven-more-languages-in-seven-weeks /book-seven-languages-in-seven-weeks #liveview /book-programming-phoenix-liveview

54 5678 23

2023-10-17 17:14:03 UTC

New

General Dev>In The News

Jan: An open source alternative to ChatGPT that runs on the desktop

Jan | Rethink the Computer. Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...

jan.ai

#desktop #chatgpt

4 5652 4

2024-03-29 08:42:30 UTC

New

Backend>Learning Resources

MySQL 9 Essentials

A concise guide to MySQL 9 database administration, covering fundamental concepts, techniques, and best practices. Neil Smyth MySQL...

pragprog.com

#pragprog #published-book /mysql /book-mysql-9-essentials

2 4162 0

2025-03-12 13:05:49 UTC

New

Programming Machine Learning:

kai

Programming Machine Learning:

Most Liked

kai

Where Next?

Popular Pragmatic Bookshelf topics

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

Hands-on Rust: question about get_component

Programming Phoenix LiveView: errata and remarks Version B2.0

A Common-Sense Guide to Data Structures and Algorithms, Second Edition: erroneous extra space complexity (page400)

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

Kotlin and Android Development featuring Jetpack: $kotlin_version ? (page 8)

Real-Time Phoenix: ProductChannelTest - undefined function describe/2 (pg 203)

Docker for Rails Developers - 'docker-machine' command deprecated (page 156)

Kotlin and Android Development featuring Jetpack: Unique constraint error when running chapter 5 code changes

Bug with dx/build - how to workaround until fix is up

Other popular topics

Web Development with Clojure, Third Edition