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
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
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
Title: Web Development with Clojure, Third Edition, vB17.0 (p9)
The create table guestbook syntax suggested doesn’t seem to be accepted ...
New
@noelrappin
Running the webpack dev server, I receive the following warning:
ERROR in tsconfig.json
TS18003: No inputs were found in c...
New
When running tox for the first time, I got the following error:
ERROR: InterpreterNotFound: python3.10
I realised that I was running ...
New
Is the book’s epub format available to read on Google Play Books?
New
I’m a newbie to Rails 7 and have hit an issue with the bin/Dev script mentioned on pages 112-113.
Iteration A1 - Seeing the list of prod...
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
Hi, I’ve got a question about the implementation of PubSub when using a Phoenix.Socket.Transport behaviour rather than channels.
Before ...
New
Is there any plan for volume 2? :slight_smile:
New
Other popular topics
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
New
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New
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...
New
We have a thread about the keyboards we have, but what about nice keyboards we come across that we want? If you have seen any that look n...
New
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
This looks like a stunning keycap set :orange_heart:
A LEGENDARY KEYBOARD LIVES ON
When you bought an Apple Macintosh computer in the e...
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:
VM Brasseur
@vmbrasseur
We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
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
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
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
- /deepseek
- /zig
- /centos
- /php
- /scala
- /react-native
- /lisp
- /sublime-text
- /textmate
- /nixos
- /debian
- /agda
- /deno
- /django
- /kubuntu
- /arch-linux
- /nodejs
- /spring
- /ubuntu
- /revery
- /manjaro
- /julia
- /lua
- /diversity
- /markdown
- /slackware









