The Math library

Kotlin provides a set of functions to perform math calculations. They can be used in a wide variety of domains such as statistics, geometry, machine learning, cryptography, and more.

List of functions

• Math.abs(...) returns the absolute value of its argument;
  
• Math.sqrt(...) returns the square root of its argument;
• Math.cbrt(...) returns the cube root of its argument;
  
• Math.pow(..., ...) returns the value of the first argument raised to the power of the second argument;
• Math.log(...) returns the natural logarithm of its argument;
• Math.min(..., ...) returns the smaller value of two arguments;
  
• Math.max(..., ...) returns the greater value of two arguments;
  
• Math.toRadians(...) converts an angle measured in degrees to an angle measured in radians (approximately);
  
• Math.sin(...) returns the trigonometric sine of the given angle in radians;
• Math.cos(...) returns the trigonometric cosine of the given angle in radians;
  
• Math.tan(...) returns the trigonometric tangent of the given angle in radians;
• Math.random() returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0;
• Math.floor(...) returns the largest double value that is less than or equal to its argument and is equal to an integer;
• Math.ceil(...) returns the smallest double value that is greater than or equal to its argument and is equal to an integer;
• Math.round(...) returns the closest integer to the argument (rounding according to the rules of arithmetic).

Also, this class has two useful constants:

• Math.PI - the ratio of the circumference of a circle to its diameter;
• Math.E - the base of the natural logarithm.

Examples

Let's see all the listed functions in practice.

val abs = Math.abs(-10)     // 10
val dabs = Math.abs(-10.33) // 10.33

val sqrt = Math.sqrt(2.0)   // 1.4142...
val cbrt = Math.cbrt(27.0)  // 3.0

val log = Math.log(Math.E * Math.E)  // 2 

val square = Math.pow(5.0, 2.0) // 25.0
val cube = Math.pow(2.0, 3.0)   // 8.0

val min = Math.min(11, 81) // 11
val max = Math.max(20, 30) // 30

val grad = Math.toRadians(30.0) // 0.5235...

val pi = Math.PI // pi is 3.1415...
val sin = Math.sin(pi / 2) // 1.0
val cos = Math.cos(pi) // 1.0
val tan = Math.tan(pi / 4) // 0.99999999... (an inaccurate result)

val random = Math.random() // a random value >= 0.0 and < 1.0

val floor = Math.floor(3.78) // 3.0
val ceil = Math.ceil(4.15)   // 5.0
val round = Math.round(4.15) // 4 (not 4.0!)

The Pythagorean Theorem

Let's assume we have a right triangle (one angle is 90 degrees). We know the lengths of both sides: a = 3.0 and b = 4.0.

To calculate the length of the hypotenuse, we can write the following code:

val a = 3.0
val b = 4.0
val c = Math.hypot(a, b) // c is 5.0

As you can see, the Math class has a lot of functions for performing numeric calculations.