joustava
Genetic Algorithms in Elixir: Code throws error (page 111)
Not sure if I’m doing something wrong here, but it seems that this piece of code will throw errors:
def fitness_function(chromosome) do
target = 'ILoveGeneticAlgorithms'
encrypted = 'LIjs`B`k`qlfDibjwlqmhv'
cipher = fn word, key -> Enum.map(word, & rem(&1 ^^^ key, 32768)) end
key =
chromosome.genes
|> Enum.map(&Integer.to_string/1)
|> Enum.join("")
|> String.to_integer(2)
guess = List.to_string(cipher.(encrypted, key))
String.jaro_distance(target, guess)
end
As
String.jaro_distance(target, guess)
Doesn’t expect ‘charlists’ but binaries
** (FunctionClauseError) no function clause matching in String.Unicode.graphemes/1
The following arguments were given to String.Unicode.graphemes/1:
# 1
'ILoveGeneticAlgorithms'
Attempted function clauses (showing 1 out of 1):
def graphemes(binary) when is_binary(binary)
(elixir 1.10.3) lib/elixir/unicode/unicode.ex:252: String.Unicode.graphemes/1
(elixir 1.10.3) lib/string.ex:2488: String.jaro_distance/2
(genetic 0.1.0) lib/genetic.ex:24: anonymous fn/2 in Genetic.evaluate/3
(elixir 1.10.3) lib/enum.ex:1396: Enum."-map/2-lists^map/1-0-"/2
(genetic 0.1.0) lib/genetic.ex:23: Genetic.evaluate/3
(genetic 0.1.0) lib/genetic.ex:116: Genetic.evolve/6
scripts/code_breaker.exs:39: (file)
I’m running this on:
⟩ elixir --version
Erlang/OTP 23 [erts-11.0.2] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe]
Elixir 1.10.3 (compiled with Erlang/OTP 23)
Not sure if something has changed recently regarding this issue.
Also, it seems the capture operator ‘&’ is in the wrong place in the book and should be moved before the call to ‘rem’ otherwise a
** (ArithmeticError) bad argument in arithmetic expression: rem(#Function<1.106933999/1 in CodeBreaker.fitness_function/1>, 32768)
:erlang.rem(#Function<1.106933999/1 in CodeBreaker.fitness_function/1>, 32768)
scripts/code_breaker.exs:16: anonymous fn/2 in CodeBreaker.fitness_function/1
(genetic 0.1.0) lib/genetic.ex:24: anonymous fn/2 in Genetic.evaluate/3
(elixir 1.10.3) lib/enum.ex:1396: Enum."-map/2-lists^map/1-0-"/2
(genetic 0.1.0) lib/genetic.ex:23: Genetic.evaluate/3
(genetic 0.1.0) lib/genetic.ex:116: Genetic.evolve/6
scripts/code_breaker.exs:33: (file)
will occur.
I think on the next page in the iex example it is the correct way.
First Post!
adkelley
Strings in Elixir are inserted between double quotes. Therefore change: target = 'ILoveGeneticAlgorithms' to: target = "ILoveGeneticAlgorithms"
Popular Pragmatic Bookshelf topics
Running the examples in chapter 5 c under pytest 5.4.1 causes an AttributeError: ‘module’ object has no attribute ‘config’.
In particula...
New
Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84:
bundle exec sequel...
New
Title: Design and Build Great Web APIs - typo “https://company-atk.herokuapp.com/2258ie4t68jv” (page 19, third bullet in URL list)
Typo:...
New
your book suggests to use Image.toByteData() to convert image to bytes, however I get the following error: "the getter ‘toByteData’ isn’t...
New
When I try the command to create a pair of migration files I get an error.
user=> (create-migration "guestbook")
Execution error (Ill...
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
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
Hi, I have just acquired Michael Fazio’s “Kotlin and Android Development” to learn about game programming for Android. I have a game in p...
New
I got this error when executing the plot files on macOS Ventura 13.0.1 with Python 3.10.8 and matplotlib 3.6.1:
programming_ML/code/03_...
New
Other popular topics
Design and develop sophisticated 2D games that are as much fun to make as they are to play. From particle effects and pathfinding to soci...
New
Curious to know which languages and frameworks you’re all thinking about learning next :upside_down_face:
Perhaps if there’s enough peop...
New
You might be thinking we should just ask who’s not using VSCode :joy: however there are some new additions in the space that might give V...
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
The V Programming Language
Simple language for building maintainable programs
V is already mentioned couple of times in the forum, but I...
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
Author Spotlight:
Peter Ullrich
@PJUllrich
Data is at the core of every business, but it is useless if nobody can access and analyze ...
New
Big O Notation can make your code faster by orders of magnitude. Get the hands-on info you need to master data structures and algorithms ...
New
This is a very quick guide, you just need to:
Download LM Studio: https://lmstudio.ai/
Click on search
Type DeepSeek, then select the o...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /haskell
- /java
- /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
- /deno
- /arch-linux
- /nodejs
- /ubuntu
- /revery
- /spring
- /manjaro
- /diversity
- /lua
- /julia
- /markdown
- /c








