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complex-numbers

A small library for the programming language Kotlin to work comfortably with complex numbers.

It includes the four basic arithmetic operations +, -, *, / and typical functions like exp, sin, cos, log, sqrt, etc.

A nice feature of Kotlin is that the operators +, -, *, / can be overloaded so that they work with all other numeric types in all combinations.

Web site

On Kotlin Math you can find further information and some examples of how to use this library.

Installation

The artifact is available on the Maven Central Repository

Maven

<groupId>org.kotlinmath</groupId>
<artifactId>complex-numbers</artifactId>
<version>1.0</version>

Gradle

compile group: 'org.kotlinmath', name: 'complex-numbers', version: '1.0'

Build

Maven (tested with version 3.6.3)

Examples

import org.kotlinmath.*

You can define the complex number 4+3i in four ways:

  • val z1 = 4 + 3.I
  • val z2 = 4 + 3 * I
  • val z3 = complex(3, 4)
  • val z4 = "4+3i".toComplex()

You can use the operators +, -, *, and / with any other numeric type:

  • val w1 = 1.5F / z1 * 2 - 4.32 + 10L + (3.toBigDecimal() * I)

There are standard function like exp, sin, cos, log and sqrt:

  • val w1 = I * z1 + exp(I * PI/2) + sqrt(-9)

.I creates a pure imaginary number; .R creates a complex number without imaginary part:

  • val two = 2.R // number two as complex number
  • val fourI = 4.I // four times i

There are constants INF, NaN (also ZERO and ONE) as infinity and "Not a Number" which can also be used for calculations:

  • -1 / ZERO == INF
  • ONE / 0 == INF
  • 3 / INF == ZERO
  • INF + INF == NaN
  • ln(0) == NaN
  • exp(INF) == NaN
  • sin(NaN) == NaN

Note that there is no -INF in complex numbers, so that -INF == INF.

Special feature

The feature of this interface is, that it provides the functions mentioned above as default implementations. But these functions could easily be replaced (overwritten) by a class which would pass the computation (for example) to the well tested Apache common package due to performance or confidence reasons.