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
As per the title, thanks.
New
page 37
ANTLRInputStream input = new ANTLRInputStream(is);
as of ANTLR 4 .8 should be:
CharStream stream = CharStreams.fromStream(i...
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
On the page xv there is an instruction to run bin/setup from the main folder. I downloaded the source code today (12/03/21) and can’t see...
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
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
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
The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error.
lib/pento_web/live/product_l...
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
Title: Agile Web Development with Rails 7: (page 70)
I am running windows 11 pro with rails 7.0.3 and ruby 3.1.2p20 (2022-04-12 revision...
New
Other popular topics
SpaceVim seems to be gaining in features and popularity and I just wondered how it compares with SpaceMacs in 2020 - anyone have any thou...
New
New
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
Create efficient, elegant software tests in pytest, Python's most powerful testing framework.
Brian Okken @brianokken
Edited by Kat...
New
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
Author Spotlight
Rebecca Skinner
@RebeccaSkinner
Welcome to our latest author spotlight, where we sit down with Rebecca Skinner, auth...
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
There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...
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
Will Swifties’ war on AI fakes spark a deepfake porn reckoning?
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /ruby
- /wasm
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /haskell
- /emacs
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /textmate
- /lisp
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /kubuntu
- /arch-linux
- /deno
- /nodejs
- /revery
- /ubuntu
- /spring
- /manjaro
- /lua
- /diversity
- /markdown
- /julia
- /c








