shawn_leong
Machine Learning in Elixir: Plot of given `profits` function does not match the expected plot (B1.0, Chapter 3, Page 65)
Hey @seanmor5,
The function given in the book
defn profits(trees) do
trees
|> Nx.pow(4)
|> Nx.negate()
|> Nx.add(Nx.multiply(2, Nx.pow(trees, 3)))
|> Nx.add(Nx.pow(trees, 2))
end
Results in the following plot which doesn’t match the expected plot in the book:
The accompanying Livebooks provides the following code to give the expected plot:
defn profits(trees) do
-((trees - 1) ** 4) + trees ** 3 + trees ** 2
end
So my guess is that there is an error in the conversion to Nx functions.
Instead, the correct translation of the Livebook function should be as follows:
defn profits(trees) do
trees
|> Nx.subtract(1)
|> Nx.pow(4)
|> Nx.negate()
|> Nx.add(Nx.pow(trees, 3))
|> Nx.add(Nx.pow(trees, 2))
end
- Adds the missing
Nx.subtract(1)that the book doesn’t have - Removes the unnecessary doubling of the cube in
Nx.add(Nx.multiply(2, Nx.pow(trees,3)))
This gives the correct expected plot
Marked As Solved
seanmor5
Author of Genetic Algorithms in Elixir
Thank you for pointing this out! I’ve fixed the issue in the next beta release!
1
Popular Pragmatic Bookshelf topics
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...
New
Hi @venkats,
It has been mentioned in the description of ‘Supervisory Job’ title that 2 things as mentioned below result in the same eff...
New
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...
New
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...
New
@noelrappin
Running the webpack dev server, I receive the following warning:
ERROR in tsconfig.json
TS18003: No inputs were found in c...
New
Running mix deps.get in the sensor_hub directory fails with the following error:
** (Mix) No SSH public keys found in ~/.ssh. An ssh aut...
New
“The ProductLive.Index template calls a helper function, live_component/3, that in turn calls on the modal component. ”
Excerpt From: Br...
New
When I run the coverage example to report on missing lines, I get:
pytest --cov=cards --report=term-missing ch7
ERROR: usage: pytest [op...
New
The allprojects block listed on page 245 produces the following error when syncing gradle:
“org.gradle.api.GradleScriptException: A prob...
New
@parrt
In the context of Chapter 4.3, the grammar Java.g4, meant to parse Java 6 compilation units, no longer passes ANTLR (currently 4....
New
Other popular topics
A thread that every forum needs!
Simply post a link to a track on YouTube (or SoundCloud or Vimeo amongst others!) on a separate line an...
New
What chair do you have while working… and why?
Is there a ‘best’ type of chair or working position for developers?
New
No chair. I have a standing desk.
This post was split into a dedicated thread from our thread about chairs :slight_smile:
New
Thanks to @foxtrottwist’s and @Tomas’s posts in this thread: Poll: Which code editor do you use? I bought Onivim! :nerd_face:
https://on...
New
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...
New
Hello everyone! This thread is to tell you about what authors from The Pragmatic Bookshelf are writing on Medium.
New
Programming Ruby is the most complete book on Ruby, covering both the language itself and the standard library as well as commonly used t...
New
Author Spotlight:
Peter Ullrich
@PJUllrich
Data is at the core of every business, but it is useless if nobody can access and analyze ...
New
A Brief Review of the Minisforum V3 AMD Tablet.
Update: I have created an awesome-minisforum-v3 GitHub repository to list information fo...
New
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...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /ruby
- /wasm
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /haskell
- /java
- /emacs
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /flutter
- /elm
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /lisp
- /textmate
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /kubuntu
- /arch-linux
- /deno
- /nodejs
- /revery
- /ubuntu
- /manjaro
- /spring
- /lua
- /diversity
- /julia
- /markdown
- /c










