Contents

dankogai/swift-complex

Complex numbers in Swift

Synopsis

import Complex
let z0 = 1.0 + 1.0.i    // (1.0+1.0.i)
let z1 = 1.0 - 1.0.i    // (1.0-1.0.i)
z0.conj // (1.0-1.0.i)
z0.i    // (-1.0+1.0.i)
z0.norm // 2
z0 + z1 // (2.0+0.0.i)
z0 - z1 // (0.0+2.0.i)
z0 * z1 // (2.0+0.0.i)
z0 / z1 // (0.0+1.0.i)

Description

complex.swift implements all the functionality of [std::complex in c++11], arguably more intuitively.

[std::complex in c++11]: http://www.cplusplus.com/reference/complex/

like C++11

  • Protocol-Oriented * Complex numbers are Complex<R> where R is a type of .real and .imag that conforms to the ComplexElement protocol or GaussianIntElement protocol.

In addition to basic arithmetic operations like +, -, , / and abs(), Complex<T:RealType> gets libm functions like exp(), log(), sin(), cos().

unlike C++11

  • Instead of defining the constant i, Double and Complex have a property .i which returns self * Complex(0,1) so it does not pollute the identifier i, too popularly used for iteration to make it a constant.
  • Following functions are provided as compouted properties:

z.abs for abs(z) z.arg for arg(z) z.norm for norm(z) z.conj for conj(z) * z.proj for proj(z)

  • Construct a complex number via polar notation as:

* Complex(abs:magnitude, arg:argument)

Usage

build

$ git clone https://github.com/dankogai/swift-complex.git
$ cd swift-complex # the following assumes your $PWD is here
$ swift build

REPL

Simply

$ swift run --repl

or

$ scripts/run-repl.sh

or

$ swift build && swift -I.build/debug -L.build/debug -lComplex

and in your repl,

Welcome to Apple Swift version 4.2 (swiftlang-1000.11.37.1 clang-1000.11.45.1). Type :help for assistance.
  1> import Complex
  2> Complex.sqrt(1.i)
$R0: Complex.Complex<Double> = {
  real = 0.70710678118654757
  imag = 0.70710678118654757
}

Xcode

Xcode project is deliberately excluded from the repository because it should be generated via swift package generate-xcodeproj . For convenience, you can

$ scripts/prep-xcode

And the Workspace opens up for you with Playground on top. The playground is written as a manual.

iOS and Swift Playground

Unfortunately Swift Package Manager does not support iOS. To make matters worse Swift Playgrounds does not support modules.

Fortunately Playgrounds allow you to include swift source codes under Sources directory. Just run:

$ scripts/ios-prep.sh

and you are all set. iOS/Complex.playground now runs on Xcode and Playgrounds on macOS, and Playgrounds on iOS (Well, it is supposed to iPadOS but it is still labeled iOS).

From Your SwiftPM-Managed Projects

Add the following to the dependencies section:

.package(
  url: "https://github.com/dankogai/swift-complex.git", from: "5.0.0"
)

and the following to the .target argument:

.target(
  name: "YourSwiftyPackage",
  dependencies: ["Complex"])

Now all you have to do is:

import Complex

in your code. Enjoy!

Prerequisite

Swift 5 or better, OS X or Linux to build.

Package Metadata

Repository: dankogai/swift-complex

Stars: 68

Forks: 7

Open issues: 0

Default branch: main

Primary language: swift

License: MIT

Topics: complex-numbers, generics, math, swift

README: README.md