kristjan.rovsek
Genetic Algorithms in Elixir: Using reinsertions (source code)
Provided source code has some problems when dealing with the reinsertions.
- scripts/schedule.exs example has a default reinsertion strategy set to “elitist”. The problem is, it actually doesn’t and is always running the default “pure” strategy because the naming of the optional parameter has a typo. Changing “reinserton_strategy” to “reinsertion_strategy” does the trick.
- If we run the script again, correct strategy is used, but now we get an “ArgumentError” in “Toolbox.Reinsertion.elitist” function when trying to sort data based on fitness.
The problem actually lies in the “Genetic.evolve” function. In it, “select” function is called which returns “parents” ( composed of pairs of chromosomes, ie: [{p1, p2}, {p3, p4}, …] ) and “leftovers” ( represented as a normal list of chromosomes, ie: [l1, l2, l3, …] ). These two get recombined in the
“Toolbox.Reinsertion.elitist” function producing a list like [{p1, p2}, {p3, p4}, l5, l6] which is of wrong format.
A solution then is to de-chunk the “parents” list before sending it to reinsertion function. Something like the following should do the trick:
parents = parents
|> Enum.reduce([],
fn {p1, p2}, acc ->
[p1, p2 | acc]
end)
- While testing this I also found that the “population_size” parameter is not working. This is because “Genetic.run” does not pass optional parameters to function “Genetic.initialize”. Changing the call to:
population = initialize(&problem.genotype/0, opts)
solves it.
Popular Pragmatic Bookshelf topics
Working through the steps (checking that the Info,plist matches exactly), run the demo game and what appears is grey but does not fill th...
New
Hello Brian,
I have some problems with running the code in your book. I like the style of the book very much and I have learnt a lot as...
New
Title: Hands-On Rust (Chapter 11: prefab)
Just played a couple of amulet-less games. With a bit of debugging, I believe that your can_p...
New
I thought that there might be interest in using the book with Rails 6.1 and Ruby 2.7.2. I’ll note what I needed to do differently here.
...
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
The generated iex result below should list products instead of product for the metadata. (page 67)
iex> product = %Product{}
%Pento....
New
Title: Intuitive Python: docker run… denied error (page 2)
Attempted to run the docker command in both CLI and Powershell
PS C:\Users\r...
New
Book: Programming Phoenix LiveView, page 142 (157/378), file lib/pento_web/live/product_live/form_component.ex, in the function below:
d...
New
When running the program in chapter 8, “Implementing Combat”, the printout Health before attack was never printed so I assumed something ...
New
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 ...
New
Other popular topics
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...
New
What chair do you have while working… and why?
Is there a ‘best’ type of chair or working position for developers?
New
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
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
Hello everyone! This thread is to tell you about what authors from The Pragmatic Bookshelf are writing on Medium.
New
Author Spotlight
Dmitry Zinoviev
@aqsaqal
Today we’re putting our spotlight on Dmitry Zinoviev, author of Data Science Essentials in ...
New
New
I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc.
However, I don’t...
New
Explore the power of Ash Framework by modeling and building the domain for a real-world web application.
Rebecca Le @sevenseacat and ...
New
Fight complexity and reclaim the original spirit of agility by learning to simplify how you develop software. The result: a more humane a...
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
- /sublime-text
- /textmate
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /spring
- /manjaro
- /diversity
- /lua
- /julia
- /markdown
- /c









