Awesome
Math Common
Math conventions to reduce boilerplate code.
Installation
Add Math Common to your Gradle build script:
repositories {
mavenCentral()
}
dependencies {
implementation("com.eriksencosta.math:common:0.2.0")
}
If you're using Maven, add to your POM xml file:
<dependency>
<groupId>com.eriksencosta.math</groupId>
<artifactId>common</artifactId>
<version>0.2.0</version>
</dependency>
Math Common is not compatible with the Android SDK at the moment.
Usage
Rounding
The library provides the Rounding strategy to make rounding
easier:
1.25.round(1) // 1.3
By default, the RoundingMode.HALF_EVEN is
used for rounding (it is the rounding logic commonly taught at school). If you want to use a different mode, create a
Rounding and use it:
import java.math.RoundingMode
val rounding = Rounding.to(2, RoundingMode.FLOOR)
rounding.round(1.257) // 1.25
rounding.round(1.253) // 1.25
// Alternatively:
1.257.round(rounding) // 1.25
1.253.round(rounding) // 1.25
If you want to round the result of a calculation, use the overloaded round() method which accepts a function as
parameter:
Rounding.to(2).round { 3.14159 * 10.0.squared() } // 314.16
Alternatively:
{ 3.14159 * 10.0.squared() }.round(2) // 314.16
Exponentiation
The extension functions squared and cubed are available for BigDecimal, Double, Float, Long, and Int:
2.squared() // 4
2.0.cubed() // 8.0
Performance
The library caches the Rounding objects by default. You can configure the cache by calling configureCache():
configureCache {
maximumItems = 100
expirationTime = 2
expirationTimeUnit = TimeUnit.HOURS
}
Rounding.to(2) === Rounding.to(2) // true
The previous example will configure the cache to store up to 100 Rounding objects, and a cached object will live for up to two hours. If you want to disable the cache, call disableCache():
disableCache()
Rounding.to(2) === Rounding.to(2) // false
API documentation
Read the API documentation for further details.