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
This test is broken right out of the box…
— FAIL: TestAgent (7.82s)
agent_test.go:77:
Error Trace: agent_test.go:77
agent_test.go:...
New
page 37
ANTLRInputStream input = new ANTLRInputStream(is);
as of ANTLR 4 .8 should be:
CharStream stream = CharStreams.fromStream(i...
New
The generated iex result below should list products instead of product for the metadata. (page 67)
iex> product = %Product{}
%Pento....
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
I found an issue in Chapter 7 regarding android:backgroundTint vs app:backgroundTint.
How to replicate:
load chapter-7 from zipfile i...
New
Hi,
I completed chapter 6 but am getting the following error when running:
thread 'main' panicked at 'Failed to load texture: IoError(O...
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
AWDWR 7, page 152, page 153:
Hello everyone,
I’m a little bit lost on the hotwire part. I didn’t fully understand it.
On page 152 @rub...
New
When running the program in chapter 8, “Implementing Combat”, the printout Health before attack was never printed so I assumed something ...
New
@mfazio23
I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game,...
New
Other popular topics
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
New
Ruby, Io, Prolog, Scala, Erlang, Clojure, Haskell. With Seven Languages in Seven Weeks, by Bruce A. Tate, you’ll go beyond the syntax—and...
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
From finance to artificial intelligence, genetic algorithms are a powerful tool with a wide array of applications. But you don't need an ...
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
Small essay with thoughts on macOS vs. Linux:
I know @Exadra37 is just waiting around the corner to scream at me “I TOLD YOU SO!!!” but I...
New
Was just curious to see if any were around, found this one:
I got 51/100:
Not sure if it was meant to buy I am sure at times the b...
New
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
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
This is cool!
DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON
We just witnessed something incredible: the largest open-s...
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
- /typescript
- /onivim
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /flutter
- /elm
- /vscode
- /ash
- /html
- /opensuse
- /deepseek
- /zig
- /centos
- /php
- /scala
- /react-native
- /lisp
- /sublime-text
- /textmate
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /ubuntu
- /spring
- /revery
- /manjaro
- /diversity
- /lua
- /julia
- /markdown
- /slackware









