In Java, the math class provides access to mathematical operations. It also provides the math operators and floating-point data types. This article introduces Java math, including Commons Math and the Java math class.

## Commons Math

Java developers can now build mathematical applications with Apache Commons Math in Java. The library provides lightweight and reusable components that tackle the most common problems in mathematics. It also provides several machine learning algorithms and optimization algorithms. The development of Commons Math was motivated by real-world application needs. This project is maintained by a team of developers.

Commons Math is composed of sixteen subpackages, each of which contains a subset of functions that can be used to perform a variety of operations. This library provides a variety of functions, including those required for basic addition, subtraction, multiplication, and division.

The library includes a number of solvers, such as the LU decomposition, which is used for equations of the form AX=B. This solver works only on square matrices, however. Other solvers are available for matrices of other shapes. The library also provides classes for vectors and two-dimensional geometry. Among the most useful classes are Vector2D, Vector3D, Line, and Segment. The first two provide data on distance between two points, while the latter gives the nearest point of a line to another line.

Commons Math also contains a collection of functions for solving mathematical problems. Many of the available methods are parallel, meaning that the number of parallel processors is lower than the number of core processors. This makes it easier to create custom methods and increase performance. For example, the division method can result in an overflow if it has a specific minimum or maximum value. Its functions are designed to be used by both developers and non-programmers alike.

Use Apache commons-math3 to do curve Fitting using Linear

```import org.hipparchus.stat.regression.SimpleRegression;
import java.util.ArrayList;
import java.util.List;
public class JavaRegression {
/**
* y = kx + b
* f(x) = 8.6x + 1.2
*/
public static double[][] linearScatters() {
List<double[]> data = new ArrayList<>();
for (double x = 0; x <= 10; x += 0.1) {
double y = 8.6 * x + 1.2;
//Generate random numbers
y += Math.random() * 4 - 2;
double[] xy = {x, y};
}
return data.stream().toArray(double[][]::new);
}
public static void main(String[] args) {
SimpleRegression reg = new SimpleRegression();
System.out.println(reg.getIntercept());
System.out.println(reg.getSlope());
System.out.println(reg.getSlopeStdErr());
}
}```

## Java’s math class

Java’s math class utility lets you do a variety of mathematical tasks with numbers. The class provides a number of static methods
The methods provided by Java’s math class are not guaranteed to return the same results. In fact, some methods offer better performance than others. Some methods will throw an ArithmeticException if the arithmetic operation overflows. However, this only happens if the value exceeds a predefined minimum or maximum.

```        /*The sqrt() method returns the square root of
the number and checks that the value is a perfect square*/
double sq = Math.sqrt(3.0);
System.out.println("sq=" + sq);
//use the abs() method to find the absolute value of a number
double absvalue=Math.abs(-2.1);
System.out.println("absvalue=" + absvalue);
//use the round() method to  return the round to number
double roundVale=Math.round(2.5);
System.out.println("roundVale=" + roundVale);```

## Java’s floating-point data types

Floating-point data types are data types that allow you to store fractional parts of numbers. Java provides two different types of floating-point numbers: single-precision floats, which are stored in 32-bits, and double-precision doubles, which are stored in 64-bits. Both types allow you to store positive and negative values, and all floating-point operations conform to the IEEE 754 standard.

The double data type is the default data type for floating-point numbers in Java. Double data types are more accurate than float, but they require more memory to store. The double data type also holds more information than the float, such as more precise values.

## Hipparchus is a fork of Apache Commons Math

Hipparchus is a fork from Apache Commons Math that provides a library of mathematical components. The project has no external dependencies and only requires Java 1.8 to run.
Hipparchus developed trigonometry and built trigonometric tables. It also solved several problems in spherical trigonometry. Is work paved the way for the development of the astrolabe and expanded the mathematical methods available to astronomers and geographers.