PragProg Customers

Programming Machine Learning: Incorrect formula

Alexandr

Alexandr

Programming Machine Learning: Incorrect formula

Hi everyone!
There is an error on the page 71 in the book “Programming machine learning from coding to depp learning” P. Perrotta. You can’t just change the weighted sum to a sigmoid without first taking the derivative of the sigmoid. See the explanation there https://yadi.sk/i/T75bWimUYPAe7Q

Best regards.

4 comments
#errata/book-programming-machine-learning
5 1341 4

Marked As Solved

nusco

nusco

Author of Metaprogramming Ruby & Programming Machine Learning

Hey, Alexandr! Thank you for taking the time to report this, and even take a picture of your notes!

I kinda regret not putting that calculation in the book, because from the explanation I wrote, it looks like the derivative of the sigmoid just disappeared. Actually, the formula in the book does take that derivative into account. The sigmoid isn’t explicit in the final formula, but it’s baked into the values of y-hat.

It’s been a while since I went through the steps myself, but I googled for a step-by-step calculation and found this one: https://medium.com/analytics-vidhya/derivative-of-log-loss-function-for-logistic-regression-9b832f025c2d

My apologies for not writing the steps by hand (busy day!), but I checked the calculation in the link above, and I cannot see any obvious errors. If you do, can you please point them out?

1
Post #2

Also Liked

Alexandr

Alexandr

Thank you!
I just read it inattentively. I think it would be a good idea to insert that link (https://medium.com/analytics-vidhya/derivative-of-log-loss-function-for-logistic-regression-9b832f025c2d) in the book.
Best regards.
P.S.
Thank you! I think you’ve written the best book for beginners( I’ve read a lot of them).

1
Post #3
nusco

nusco

Author of Metaprogramming Ruby & Programming Machine Learning

No problem, Alexandr, and thank you for reporting the issue anyway!

1
Post #4

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
Home PragProg Customers
#errata/book-programming-machine-learning
5 1341 4
Last post

Popular Pragmatic Bookshelf topics Top

johnp
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
New
herminiotorres
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
New
AleksandrKudashkin
PragProg Customers

Modern Front-End Development for Rails: B7 no main folder in the source code (page xv)
On the page xv there is an instruction to run bin/setup from the main folder. I downloaded the source code today (12/03/21) and can’t see...
#errata/book-modern-front-end-development-for-rails
2 1452 11
New
alanq
PragProg Customers

Modern Front-End Development for Rails: Can't get TURBO_STREAM format in some cases
This isn’t directly about the book contents so maybe not the right forum…but in some of the code apps (e.g. turbo/06) it sends a TURBO_ST...
#question/book-modern-front-end-development-for-rails
1 1386 7
New
patoncrispy
PragProg Customers

Hands-on Rust: Adequate docs for bracket_lib
I’m new to Rust and am using this book to learn more as well as to feed my interest in game dev. I’ve just finished the flappy dragon exa...
#question/book-hands-on-rust
5 1516 3
New
hazardco
PragProg Customers

Agile Web Development with Rails 7: Example code does not work delete method (page 78)
On page 78 the following code appears: <%= link_to ‘Destroy’, product, class: ‘hover:underline’, method: :delete, data: { confirm...
#suggestion/book-agile-web-development-with-rails-7
1 1266 2
New
mert
PragProg Customers

Agile Web Development with Rails 7: page 152, page 153:
AWDWR 7, page 152, page 153: Hello everyone, I’m a little bit lost on the hotwire part. I didn’t fully understand it. On page 152 @rub...
#question/book-agile-web-development-with-rails-7
0 1230 4
New
tkhobbes
PragProg Customers

Modern Front-End Development for Rails - application does not start after run bin/setup (page xviii)
After some hassle, I was able to finally run bin/setup, now I have started the rails server but I get this error message right when I vis...
#errata/book-modern-front-end-development-for-rails
0 1461 5
New
redconfetti
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
New
dachristenson
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
New

Other popular topics Top

PragmaticBookshelf
Backend>Learning Resources

Programming Machine Learning
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
pragprog.com
#pragprog#ai/python#published-book/book-programming-machine-learning#math#algorithms
6 5350 3
New
AstonJ
Backend>Questions

Erlang's not installing on macOS Big Sur "You are natively building Erlang/OTP for a later version of MacOSX than current version"
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting: asdf install erlang 23.1.2 Configure failed. checking ...
#macos/erlang#big-sur#asdf
10 6212 8
New
AstonJ
General Dev>Hardware

Planck vs Preonic vs Subatomic (Keyboards)
I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me. I think the Planck and the Preonic (o...
/keyboards#mechanical-keyboards#ortholinear#planck#preonic
105 17596 47
New
PragmaticBookshelf
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
New
DevotionGeo
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
New
AstonJ
General Dev>Code Editors

Doom-Emacs: Can't find emacs in your PATH
If you get Can't find emacs in your PATH when trying to install Doom Emacs on your Mac you… just… need to install Emacs first! :lol: bre...
#macos/emacs#doom-emacs
4 5837 0
New
PragmaticBookshelf
Backend>Learning Resources

C Brain Teasers
25 puzzles that will make you a better C programmer by challenging your knowledge of the language, and explaining the technical details o...
pragprog.com
#pragprog#published-book/c/book-c-brain-teasers
4 3873 2
New
First poster: AstonJ
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
New
PragmaticBookshelf
Backend>Learning Resources

Risk-First Software Development, Second Edition
As digital systems increasingly run the world, mastery of the recurring patterns of software development risk is the key to fast and effe...
pragprog.com
#pragprog#published-book/book-risk-first-software-development-second-edition
12 4217 8
New
PragmaticBookshelf
Backend>Learning Resources

Eloquent Ruby, Second Edition
Write elegant Ruby code—not just correct, but idiomatic. Go beyond the vocabulary and syntax and learn to express yourself with eloquence...
pragprog.com
#pragprog/ruby#published-book/book-eloquent-ruby-second-edition
11 7668 8
New
Back to top

Latest in Programming Machine Learning

Programming Machine Learning Portal ❯

PragProg Customers

Pragmatic Bookshelf PragProg Customers ❯

Latest on Devtalk

Devtalk ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap