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: pytest now requires markers to be declared (downloadable code)

Many tasks_proj/tests directories exist in chapters 2, 3, 5 that have tests that use the custom markers smoke and get, which are not decl...

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

2 1383 2

2021-02-16 14:15:02 UTC

New

PragProg Customers

Design and Build Great Web APIs: typo (page, 19, third bullet in URL list)

Title: Design and Build Great Web APIs - typo “https://company-atk.herokuapp.com/2258ie4t68jv” (page 19, third bullet in URL list) Typo:...

#pragprog #errata /book-design-and-build-great-web-apis

8 1941 7

2023-04-13 12:45:23 UTC

New

PragProg Customers

Web Development with Clojure, Third Edition: Issue adding Shadow CLJS

Title: Web Development with Clojure, Third Edition, pg 116 Hi - I just started chapter 5 and I am stuck on page 116 while trying to star...

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

4 1199 4

2021-01-10 05:30:17 UTC

New

PragProg Customers

Programming Phoenix LiveView: Typo

Hi! I know not the intentions behind this narrative when called, on page XI: mount() |> handle_event() |> render() but the correc...

#errata /book-programming-phoenix-liveview

3 1307 17

2021-03-11 16:34:20 UTC

New

PragProg Customers

Python Testing with pytest, Second Edition: unrecognized arguments error (page 122)

When I run the coverage example to report on missing lines, I get: pytest --cov=cards --report=term-missing ch7 ERROR: usage: pytest [op...

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

0 4000 1

2021-12-03 05:36:38 UTC

New

PragProg Customers

Hands-on Rust: Failed to Load Texture error (page 121)

Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...

/book-hands-on-rust

2 1310 3

2022-01-23 22:36:50 UTC

New

PragProg Customers

Real Time Phoenix Errata P17: Getting first sample working with Phoenix 1.6.x

Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...

#errata /book-real-time-phoenix

6 1116 5

2022-12-08 12:49:23 UTC

New

PragProg Customers

Agile Web Development with Rails 7: Reloading assets in development mode

Hi all, currently I wonder how the Tailwind colours work (or don’t work). For example, in app/views/layouts/application.html.erb I have...

#question /book-agile-web-development-with-rails-7

2 1380 4

2022-02-18 10:00:49 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

PragProg Customers

Kotlin and Android Development featuring Jetpack: End Ch. 11 app runs but consistently crashes

I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...

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

0 936 8

2024-01-05 05:43:55 UTC

New

Other popular topics

Backend>Learning Resources

Seven Languages in Seven Weeks

Ruby, Io, Prolog, Scala, Erlang, Clojure, Haskell. With Seven Languages in Seven Weeks, by Bruce A. Tate, you’ll go beyond the syntax—and...

pragprog.com

#pragprog /clojure /erlang /haskell /prolog /ruby /scala #published-book /book-seven-languages-in-seven-weeks

5 5730 1

2022-01-20 13:48:55 UTC

New

Backend>Learning Resources

Testing Elixir

Write Elixir tests that you can be proud of. Dive into Elixir’s test philosophy and gain mastery over the terminology and concepts that u...

pragprog.com

#pragprog /elixir #published-book /book-testing-elixir

33 5004 8

2021-01-05 06:17:50 UTC

New

Science/Tech>Health & Diet

How do you keep fit and healthy?

@AstonJ prompted me to open this topic after I mentioned in the lockdown thread how I started to do a lot more for my fitness. https://f...

#fitness #heath

193 4981 82

2023-01-23 06:00:46 UTC

New

Community>Journals

Programming Erlang Book Club

My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...

/erlang /book-programming-erlang-2nd-edition #book-club

195 6815 95

2025-02-16 20:22:17 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

Science/Tech>Health & Diet

David Sinclair's new Lifespan podcast

We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...

#health #podcasts #bio-hackers #david-sinclair

87 6790 49

2022-04-12 16:27:36 UTC

New

Backend>Learning Resources

Effective Haskell

Build efficient applications that exploit the unique benefits of a pure functional language, learning from an engineer who uses Haskell t...

pragprog.com

#pragprog /haskell #published-book /book-effective-haskell

15 10218 1

2022-02-16 10:09:51 UTC

New

Community>In The Spotlight

Spotlight: Mike Riley (Author) Interview and AMA!

Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...

#author-spotlight /python #iot /book-portable-python-projects #internet-of-things

62 7035 19

2022-06-09 14:01:01 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

Android>Questions

Unresolved Reference to android in build.gradle.kts – Beginner Issue

Hello, I’m a beginner in Android development and I’m facing an issue with my project setup. In my build.gradle.kts file, I have the foll...

#binding

0 7460 2

2024-12-09 21:07:33 UTC

New

Programming Machine Learning:

kai

Programming Machine Learning:

Most Liked

kai

Where Next?

Popular Pragmatic Bookshelf topics

Python Testing with pytest: pytest now requires markers to be declared (downloadable code)

Design and Build Great Web APIs: typo (page, 19, third bullet in URL list)