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

Web Development with Clojure, Third Edition: migrations/create not working: p159

Title: Web Development with Clojure, Third Edition - migrations/create not working: p159 When I execute the command: user=> (create-...

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

5 1084 2

2020-11-14 22:24:32 UTC

New

PragProg Customers

Programming Phoenix LiveView: P27, live_path confusion

I am working on the “Your Turn” for chapter one and building out the restart button talked about on page 27. It recommends looking into ...

#question /book-programming-phoenix-liveview

7 3505 14

2023-08-09 13:36:28 UTC

New

PragProg Customers

Intuitive Python: docker run… denied error (page 2)

Title: Intuitive Python: docker run… denied error (page 2) Attempted to run the docker command in both CLI and Powershell PS C:\Users\r...

#errata /book-intuitive-python

9 1263 4

2021-04-06 16:33:24 UTC

New

PragProg Customers

Python Testing with pytest, Second Edition: File not Found Error (page 43)

I ran this command after installing the sample application: $ cards add do something --owner Brian And got a file not found error: Fil...

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

5 4391 7

2021-07-03 13:51:08 UTC

New

PragProg Customers

Build a Weather Station with Elixir and Nerves: Problem connecting to Postgres with Grafana

Title: Build a Weather Station with Elixir and Nerves: Problem connecting to Postgres with Grafana on (page 64) If you follow the defau...

#errata /book-build-a-weather-station-with-elixir-and-nerves

0 1962 4

2021-11-16 04:25:39 UTC

New

PragProg Customers

Programming Phoenix LiveView: book not updated to version 1.6 (p. 18)

In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...

#errata /book-programming-phoenix-liveview

9 2051 12

2022-02-08 11:31:40 UTC

New

PragProg Customers

Python Testing with pytest, Second Edition: error when running tox in parallel (page 151)

When trying to run tox in parallel as explained on page 151, I got the following error: tox: error: argument -p/–parallel: expected one...

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

0 1111 1

2021-12-10 05:12:17 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: (page 70)

Title: Agile Web Development with Rails 7: (page 70) I am running windows 11 pro with rails 7.0.3 and ruby 3.1.2p20 (2022-04-12 revision...

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

0 1129 1

2022-06-08 13:17:16 UTC

New

PragProg Customers

Programming Machine Learning: Setting up your system (p 13)

From page 13: On Python 3.7, you can install the libraries with pip by running these commands inside a Python venv using Visual Studio ...

#question /book-programming-machine-learning

1 989 3

2023-10-09 07:44:15 UTC

New

Other popular topics

Game Dev>Learning Resources

The Ray Tracer Challenge

Brace yourself for a fun challenge: build a photorealistic 3D renderer from scratch! In just a couple of weeks, build a ray tracer that r...

pragprog.com

#pragprog #published-book /book-the-ray-tracer-challenge #algorithms

3 6115 0

2020-09-22 14:26:56 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

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

Linux>Questions

AMD or Intel for Programming with Linux as the OS?

I am thinking in building or buy a desktop computer for programing, both professionally and on my free time, and my choice of OS is Linux...

#mobile #android #web-development #linux #desktop-computer #mobile-development

36 6006 10

2020-07-12 20:50:05 UTC

New

General Dev>Dev Chat

Which vertical monitor do you use?

I’m thinking of buying a monitor that I can rotate to use as a vertical monitor? Also, I want to know if someone is using it for program...

#monitors #programming

51 4892 20

2023-06-28 07:23:42 UTC

New

General Dev>Code Editors

SpaceVim vs SpaceMacs

SpaceVim seems to be gaining in features and popularity and I just wondered how it compares with SpaceMacs in 2020 - anyone have any thou...

/vim #spacevim #spacemacs /emacs #code-editors

30 4336 14

2020-08-27 17:53:29 UTC

New

macOS>Chat

My thoughts on macOS vs Linux

Small essay with thoughts on macOS vs. Linux: I know @Exadra37 is just waiting around the corner to scream at me “I TOLD YOU SO!!!” but I...

#macos #linux

166 9730 69

2021-04-10 22:36:29 UTC

New

General Dev>Sales

Get 50% off these PragProg books during our Think Again Sale

Think Again 50% Off Sale » The theme of this sale is new perspectives on familiar topics. Enter coupon code ThinkAgain2021 at checkout t...

#community #pragprog /elixir /book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition /book-programming-machine-learning /book-the-ray-tracer-challenge /book-forge-your-future-with-open-source /book-software-design-x-rays #algorithms /book-testing-elixir #machine-learning #sale /book-concurrent-data-processing-in-elixir /book-intuitive-python

8 6415 2

2021-05-11 23:06:15 UTC

New

Backend>Learning Resources

Programming WebRTC

Use WebRTC to build web applications that stream media and data in real time directly from one user to another, all in the browser. ...

pragprog.com

#pragprog #published-book /js #webrtc /book-programming-webrtc

27 6969 6

2021-11-20 19:03:04 UTC

New

AI>Questions

What are the best text-to-speech ai generation tools that you can run locally?

Background Lately I am in a quest to find a good quality TTS ai generation tool to run locally in order to create audio for some videos I...

#ai #text-to-speech

6 7713 3

2025-03-24 16:48:39 UTC

New

Programming Machine Learning:

kai

Programming Machine Learning:

Most Liked

kai

Where Next?

Popular Pragmatic Bookshelf topics

Web Development with Clojure, Third Edition: migrations/create not working: p159

Programming Phoenix LiveView: P27, live_path confusion

Intuitive Python: docker run… denied error (page 2)

Python Testing with pytest, Second Edition: File not Found Error (page 43)

Build a Weather Station with Elixir and Nerves: Problem connecting to Postgres with Grafana

Programming Phoenix LiveView: book not updated to version 1.6 (p. 18)

Python Testing with pytest, Second Edition: error when running tox in parallel (page 151)

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

Agile Web Development with Rails 7: (page 70)

Programming Machine Learning: Setting up your system (p 13)