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

Web Development with Clojure, Third Edition: (create-migration "guestbook") not working (page 9)

When I try the command to create a pair of migration files I get an error. user=> (create-migration "guestbook") Execution error (Ill...

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

5 1788 4

2023-07-27 14:17:36 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

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

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

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

Programming Phoenix LiveView: Live Upload Match Error

Book: Programming Phoenix LiveView, page 142 (157/378), file lib/pento_web/live/product_live/form_component.ex, in the function below: d...

#errata /book-programming-phoenix-liveview

7 1158 10

2023-01-26 13:23:12 UTC

New

PragProg Customers

Programming Phoenix LiveView: PentoWeb.LayoutView errata (56)

root_layout: {PentoWeb.LayoutView, :root}, This results in the following following error: no “root” html template defined for PentoWeb...

#errata /book-programming-phoenix-liveview

8 1094 4

2023-10-22 17:25:26 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

General Dev>Learning Resources

A Common-Sense Guide to Data Structures and Algorithms, Second Edition

Algorithms and data structures are much more than abstract concepts. Mastering them enables you to write code that runs faster and more e...

pragprog.com

#pragprog /python /ruby #published-book /book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition #math #algorithms /js

19 6022 5

2020-08-14 00:58:37 UTC

New

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

Data Science

Can AI/ML predict a lottery win?

Biggest jackpot ever apparently! :upside_down_face: I don’t (usually) gamble/play the lottery, but working on a program to predict the...

#ai #machine-learning

19 3939 10

2021-10-18 19:01:41 UTC

New

General Dev>Dev Chat

Roc Language - a new purely functional programming language built for speed and ergonomics

Hi folks, I don’t know if I saw this here but, here’s a new programming language, called Roc Reminds me a bit of Elm and thus Haskell. ...

#programminguages #functional-programming

49 5164 14

2021-11-10 20:03:09 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

Game Dev>Questions

Can I use Java to program a game for Nintendo switch?

I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...

/java #nintendo

8 4771 3

2023-09-15 11:15:04 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

General Dev>In The News

Zig now has built-in HTTP server and client in std

zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig. General-purpose programming language and toolchain for maintaini...

github.com

/zig #http

0 5624 0

2023-05-19 00:35:41 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

Game Dev>Questions

I want to learn how make a game, but where should I start?

I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc. However, I don’t...

#game-dev

15 4965 9

2025-10-18 13:12:58 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