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

Modern CSS with Tailwind: can’t setup the Rails source code

I can’t setup the Rails source code. This happens in a working directory containing multiple (postgres) Rails apps. With: ruby-3.0.0 s...

#question /book-modern-css-with-tailwind

0 1280 3

2021-03-27 15:29:34 UTC

New

PragProg Customers

Modern CSS with Tailwind: setting up Rails app

In case this helps anyone, I’ve had issues setting up the rails source code. Here were the solutions: In Gemfile, change gem 'rails' t...

#errata /book-modern-css-with-tailwind

3 1278 2

2022-01-05 00:19:21 UTC

New

PragProg Customers

Domain Modeling Made Functional: Missing diagram on page 18

The book has the same “Problem space/Solution space” diagram on page 18 as is on page 17. The correct Problem/Solution space diagrams ar...

#errata /book-domain-modeling-made-functional

1 1078 1

2021-09-11 17:34:22 UTC

New

PragProg Customers

Distributed Services with Go: receiving Unknown flag: --go_opt when compiling protobuf (page 20)

When trying to generate the protobuf .go file, I receive this error: Unknown flag: --go_opt libprotoc 3.12.3 MacOS 11.3.1 Googling ...

/book-distributed-services-with-go

0 4924 3

2021-08-18 18:19:51 UTC

New

PragProg Customers

Build a Weather Station with Elixir and Nerves: SGP30 vs SGP40

This is as much a suggestion as a question, as a note for others. Locally the SGP30 wasn’t available, so I ordered a SGP40. On page 53, ...

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

0 1292 2

2024-03-20 19:56:42 UTC

New

PragProg Customers

Kotlin and Android Development featuring Jetpack: Error in generated Game.java (page 136)

I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...

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

2 1172 8

2021-09-17 18:06:54 UTC

New

PragProg Customers

Distributed Services With Go: Unable to pass readiness/liveness checks. (page 210, 215)

I’m not quite sure what’s going on here, but I’m unable to have to containers successfully complete the Readiness/Liveness checks. I’m im...

/book-distributed-services-with-go

5 1420 5

2022-08-31 00:14:29 UTC

New

PragProg Customers

The Ray Tracer Challenge: cannot pass scaling test (page 69-70)

The test is as follows: Scenario: Intersecting a scaled sphere with a ray Given r ← ray(point(0, 0, -5), vector(0, 0, 1)) And s ← sphere...

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

1 1093 4

2022-07-27 09:47:44 UTC

New

PragProg Customers

Kotlin and Android Development featuring Jetpack: No activity_main.xml anymore

I just bought this book to learn about Android development, and I’m already running into a major issue in Ch. 1, p. 20: “Update activity...

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

0 2172 6

2023-08-15 06:19:56 UTC

New

Other popular topics

General Dev>Hardware

What monitor(s) do you have for programming?

Please tell us what is your preferred monitor setup for programming(not gaming) and why you have chosen it. Does your monitor have eye p...

#monitors #coding #programming #development

227 11362 88

2022-02-01 12:02:08 UTC

New

Backend>Questions

Can someone explain the -t option/flag in docker run command?

I know that -t flag is used along with -i flag for getting an interactive shell. But I cannot digest what the man page for docker run com...

#docker

7 10261 2

2020-09-01 07:19:16 UTC

New

General Dev>Dev Chat

Languages Without Garbage Collection

Continuing the discussion from Thinking about learning Crystal, let’s discuss - I was wondering which languages don’t GC - maybe we can c...

#garbage-collection

21 5575 7

2021-05-06 05:54:58 UTC

New

AI>In The News

How to fix the eyes in AI-generated images

aidemos.info

0 4508 0

2022-09-10 13:54:33 UTC

New

Windows>Chat

Taskbar Overflow Menu (NOT System Tray Overflow)

There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...

#taskbar-overflow-win-11

3 3715 2

2023-02-13 08:43:55 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>Official News

Node.js v22.14.0 released!

Node.js v22.14.0 has been released. Link: Release 2025-02-11, Version 22.14.0 'Jod' (LTS), @aduh95 · nodejs/node · GitHub

github.com

/nodejs #official-news

0 4251 0

2025-02-11 15:30:14 UTC

New

Community>In The Spotlight

AMA with: Mark Volkmann (codebar Winter Lit Fest)

Ask Me Anything with Mark Volkmann @mvolkmann On February 24 and 25, we are giving you a chance to ask questions of PragProg author M...

/book-server-driven-web-apps-with-htmx #codebar-spotlight

37 3100 20

2025-02-26 21:39:39 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

General Dev>Reviews

Keyboard Review: UHK60V2 vs Defy vs Voyager vs Glove80 vs Svalboard

Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...

/keyboards #uhk60v2 #defy #voyager #glove80 #svalboard

5 5681 7

2025-04-21 21:44:45 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)

Modern CSS with Tailwind: can’t setup the Rails source code

Modern CSS with Tailwind: setting up Rails app

Domain Modeling Made Functional: Missing diagram on page 18

Distributed Services with Go: receiving Unknown flag: --go_opt when compiling protobuf (page 20)

Build a Weather Station with Elixir and Nerves: SGP30 vs SGP40

Kotlin and Android Development featuring Jetpack: Error in generated Game.java (page 136)

Distributed Services With Go: Unable to pass readiness/liveness checks. (page 210, 215)

The Ray Tracer Challenge: cannot pass scaling test (page 69-70)

Kotlin and Android Development featuring Jetpack: No activity_main.xml anymore

Other popular topics

What monitor(s) do you have for programming?