expm1

数学类静态double expm1(double d) (Math Class static double expm1(double d))

• This method is available in java.lang package.

  此方法在java.lang包中可用。

• This method is used to return [ the exponential of the given number – 1] in the method or in other words it is used to calculate the ( e raised to the power of the given argument – 1). 

  此方法用于返回方法中的[给定数字的指数– 1]，或换句话说，它用于计算(e升至给定参数的幂– 1)。

• In this method, expm stands for exponentiation. 

  在此方法中，expm代表求幂。

• This is a static method so this method is accessible with the class name too. 

  这是一个静态方法，因此也可以使用类名访问此方法。

• The return type of this method is double that means it returns (The exponentiation of the given argument -1) and the argument and return value are of double type. 

  此方法的返回类型为double，表示它返回(给定参数-1的幂)，并且参数和返回值均为double类型。

• In this method we pass only one parameter as an argument in the method of Math class and the given parameter is the exponent to raise the power of e -1. 

  在此方法中，我们仅将一个参数作为参数传递给Math类的方法，并且给定参数是提高e -1幂的指数。

• This method does not throw any exception.

  此方法不会引发任何异常。

Syntax:

句法：

    public static double expm1(double d){
}

Parameter(s):

参数：

double d – A double value whose exponential to be found..

double d –一个要找到其指数的double值。

Note:

注意：

• If we pass "NaN" to the function, it returns the "NaN".

  如果我们将“ NaN”传递给函数，它将返回“ NaN”。

• If we pass positive infinity, it returns the positive infinity.

  如果我们传递正无穷大，它将返回正无穷大。

• If we pass negative infinity, it returns -1.0.

  如果传递负无穷大，则返回-1.0。

• If we pass zero (-0 or 0), it returns 0.0.

  如果传递零(-0或0)，则返回0.0。

Return value:

返回值：

The return type of this method is double, it returns the exponentiation of the given value.

此方法的返回类型为double ，它返回给定值的幂。

Java程序演示expm1(double d)方法的示例 (Java program to demonstrate example of expm1(double d) method)

// Java program to demonstrate the example of expm1(double d) 
// method of Math Class
public class Expm1Method {
public static void main(String[] args) {
// Here we are declaring few variables
double d1 = 7.0 / 0.0;
double d2 = -7.0 / 0.0;
double d3 = 0.0;
double d4 = -0.0;
double d5 = 0.8;
double d6 = 2;
// Display previous value of d1,d2,d3, d4,d5 and d6 
System.out.println(" Before implementing expm1() so the value of d1 is :" + d1);
System.out.println(" Before implementing expm1() so the value of d2 is :" + d2);
System.out.println(" Before implementing expm1() so the value of d3 is :" + d3);
System.out.println(" Before implementing expm1() so the value of d4 is :" + d4);
System.out.println(" Before implementing expm1() so the value of d5 is :" + d5);
System.out.println(" Before implementing expm1() so the value of d6 is :" + d6);
// Here , we will get (Infinity) because we are passing parameter 
// whose value is (infinity)
System.out.println("After implementing expm1() so the value of d1 is :" + Math.expm1(d1));
// Here , we will get (-1.0) because we are passing parameter 
// whose value is (-infinity)
System.out.println("After implementing expm1() so the value of d2 is :" + Math.expm1(d2));
// Here , we will get (0.0) because we are passing parameter 
// whose value is (0.0)
System.out.println("After implementing expm1() so the value of d3 is :" + Math.expm1(d3));
// Here , we will get (-0.0) because we are passing parameter 
// whose value is (-0.0)
System.out.println("After implementing expm1() so the value of d4 is :" + Math.expm1(d4));
// Here , we will get [(e raised to the power of 0.8) - 1] 
// because we are passing parameter whose value is (0.8)
System.out.println("After implementing expm1() so the value of d5 is :" + Math.expm1(d5));
// Here , we will get [(e raised to the power of 2) - 1] 
// because we are passing parameter whose value is (2)
System.out.println("After implementing expm1() so the value of d6 is :" + Math.expm1(d6));
}
}

Output

输出量

E:\Programs>javac Expm1Method.java
E:\Programs>java Expm1Method
Before implementing expm1() so the value of d1 is :Infinity
Before implementing expm1() so the value of d2 is :-Infinity
Before implementing expm1() so the value of d3 is :0.0
Before implementing expm1() so the value of d4 is :-0.0
Before implementing expm1() so the value of d5 is :0.8
Before implementing expm1() so the value of d6 is :2.0
After implementing expm1() so the value of d1 is :Infinity
After implementing expm1() so the value of d2 is :-1.0
After implementing expm1() so the value of d3 is :0.0
After implementing expm1() so the value of d4 is :-0.0
After implementing expm1() so the value of d5 is :1.2255409284924677
After implementing expm1() so the value of d6 is :6.38905609893065

翻译自: https://www.includehelp.com/java/math-class-static-double-expm1-double-d-with-example.aspx

expm1