org.kotlinmath:complex-numbers

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 http://kotlinmath.org you can find further information and some examples of how to use this library.

Build

Maven (tested with version 3.6.3)

Examples

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.