inreoh
Genetic Algorithms in Elixir: wrong syntax in ch. 4, termination criteria for one_max ?
@seanmor5
In chapter 4 of p1.0 (page 89 of 262 in the epub version), the code for the avg termination criterion looks like this:
def terminate?(population) do
avg =
population
|> Enum.map(&(Enum.sum(&1) / length(&1)))
avg == 21
end
For me, this causes a syntax error:
protocol Enumerable not implemented for %Types.Chromosome
Presumably because the call to fitness_function() is missing. This version works for me:
avg =
population
|> Enum.map(&OneMax.fitness_function/1)
|> Enum.sum()
|> (fn x -> x / length(population) end).()
although it’s not very elegant (esp. the last line looks ugly), so I’d much prefer something closer to the original version.
Popular Pragmatic Bookshelf topics
Title: Web Development with Clojure, Third Edition, pg 116
Hi - I just started chapter 5 and I am stuck on page 116 while trying to star...
New
Hi Jamis,
I think there’s an issue with a test on chapter 6. I own the ebook, version P1.0 Feb. 2019.
This test doesn’t pass for me:
...
New
Title: Hands-on Rust: question about get_component (page 295)
(feel free to respond. “You dug you’re own hole… good luck”)
I have somet...
New
Hi Travis! Thank you for the cool book! :slight_smile:
I made a list of issues and thought I could post them chapter by chapter. I’m rev...
New
Hi,
build fails on:
bracket-lib = “~0.8.1”
when running on Mac Mini M1 Rust version 1.5.0:
Compiling winit v0.22.2
error[E0308]: mi...
New
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...
New
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...
New
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...
New
When trying to run tox in parallel as explained on page 151, I got the following error:
tox: error: argument -p/–parallel: expected one...
New
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 ...
New
Other popular topics
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...
New
Saw this on TikTok of all places! :lol:
Anyone heard of them before?
Lite:
New
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. ...
New
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
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...
New
Author Spotlight
Jamis Buck
@jamis
This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
Author Spotlight
Rebecca Skinner
@RebeccaSkinner
Welcome to our latest author spotlight, where we sit down with Rebecca Skinner, auth...
New
Will Swifties’ war on AI fakes spark a deepfake porn reckoning?
New
I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc.
However, I don’t...
New
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...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /emacs
- /haskell
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /deepseek
- /centos
- /php
- /scala
- /react-native
- /lisp
- /textmate
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /spring
- /manjaro
- /lua
- /diversity
- /julia
- /markdown
- /v









