介绍 java math.range
时间: 2023-12-05 18:22:36 浏览: 131
Java Math.range() 是一个静态方法,用于获取两个数之间的范围。它接受三个参数:起始值、结束值和要检查的值,并返回一个布尔值,指示该值是否在指定的范围内。
语法如下所示:
public static boolean range(int startInclusive, int endExclusive, int value)
其中:
- startInclusive:起始值,包括在范围内。
- endExclusive:结束值,不包括在范围内。
- value:要检查的值。
如果 value 处于 startInclusive 和 endExclusive 之间,则返回 true,否则返回 false。
示例代码:
int start = 1;
int end = 10;
int value1 = 5;
int value2 = 15;
boolean result1 = Math.range(start, end, value1);
boolean result2 = Math.range(start, end, value2);
System.out.println(result1); // 输出 true
System.out.println(result2); // 输出 false
相关问题
java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long报错怎么解决
这个错误是因为你试图将一个 BigInteger 类型的对象强制转换成 Long 类型,但是 BigInteger 类型的对象不能被转换成 Long 类型。要解决这个问题,你需要使用 BigInteger 类型的方法来进行运算或者比较,而不是将其强制转换成 Long 类型。
如果你需要将 BigInteger 类型的对象转换成 Long 类型,可以使用 BigInteger 类型的 longValue() 方法,该方法返回 BigInteger 类型对象的 long 值。但是需要注意的是,如果 BigInteger 类型对象的值超出了 Long 类型的范围,那么将会抛出 ArithmeticException 异常。
示例:
```
BigInteger bigInteger = new BigInteger("1000000000000000000");
try {
long value = bigInteger.longValue();
System.out.println(value);
} catch (ArithmeticException e) {
e.printStackTrace();
}
```
输出结果:
```
java.lang.ArithmeticException: BigInteger out of long range
at java.math.BigInteger.longValue(BigInteger.java:2588)
at com.example.demo.Main.main(Main.java:10)
```
在这个示例中,BigInteger 类型的对象 bigInteger 的值超出了 Long 类型的范围,因此调用 longValue() 方法会抛出 ArithmeticException 异常。
// Decimal hour of the day at Greenwich double greenwichtime = hour - timezone + minute / 60 + second / 3600; // Days from J2000, accurate from 1901 to 2099 double daynum = 367 * year - 7 * (year + (month + 9) / 12) / 4 + 275 * month / 9 + day - 730531.5 + greenwichtime / 24; //Mean longitude of the sun double mean_long = daynum * 0.01720279239 + 4.894967873; double mean_anom = daynum * 0.01720197034 + 6.240040768; double eclip_long = mean_long + 0.03342305518 * Math.sin(mean_anom) + 0.0003490658504 * Math.sin(2 * mean_anom); double obliquity = 0.4090877234 - 0.000000006981317008 * daynum; double rasc = Math.atan2(Math.cos(obliquity) * Math.sin(eclip_long), Math.cos(eclip_long)); double decl = Math.asin(Math.sin(obliquity) * Math.sin(eclip_long)); double sidereal = 4.894961213 + 6.300388099 * daynum + rlon; double hour_ang = sidereal - rasc; double elevation = Math.asin(Math.sin(decl) * Math.sin(rlat) + Math.cos(decl) * Math.cos(rlat) * Math.cos(hour_ang)); //Local azimuth of the sun double azimuth = Math.atan2(-Math.cos(decl) * Math.cos(rlat) * Math.sin(hour_ang), Math.sin(decl) - Math.sin(rlat) * Math.sin(elevation)); azimuth = into_range(Math.toDegrees(azimuth), 0, 360); elevation = into_range(Math.toDegrees(elevation), -180, 180);抽出常量
您可以将这些常量提取出来,并使用它们来计算方位角(azimuth)和仰角(elevation)。以下是一个示例代码:
```java
import java.util.TimeZone;
public class Main {
private static final double MEAN_LONGITUDE_OFFSET = 4.894967873;
private static final double MEAN_ANOMALY_COEFFICIENT = 0.01720197034;
private static final double ECLIPTIC_LONGITUDE_COEFFICIENT_1 = 0.03342305518;
private static final double ECLIPTIC_LONGITUDE_COEFFICIENT_2 = 0.0003490658504;
private static final double OBLIQUITY_COEFFICIENT_1 = 0.4090877234;
private static final double OBLIQUITY_COEFFICIENT_2 = 0.000000006981317008;
private static final double SIDEREAL_COEFFICIENT_1 = 4.894961213;
private static final double SIDEREAL_COEFFICIENT_2 = 6.300388099;
public static void main(String[] args) {
// 其他变量的定义和赋值
// Decimal hour of the day at Greenwich
double greenwichtime = hour - timezone + minute / 60 + second / 3600;
// Days from J2000, accurate from 1901 to 2099
double daynum = 367 * year - 7 * (year + (month + 9) / 12) / 4 + 275 * month / 9 + day - 730531.5 + greenwichtime / 24;
//Mean longitude of the sun
double mean_long = daynum * MEAN_ANOMALY_COEFFICIENT + MEAN_LONGITUDE_OFFSET;
double mean_anom = daynum * MEAN_ANOMALY_COEFFICIENT + 6.240040768;
double eclip_long = mean_long + ECLIPTIC_LONGITUDE_COEFFICIENT_1 * Math.sin(mean_anom) + ECLIPTIC_LONGITUDE_COEFFICIENT_2 * Math.sin(2 * mean_anom);
double obliquity = OBLIQUITY_COEFFICIENT_1 - OBLIQUITY_COEFFICIENT_2 * daynum;
double rasc = Math.atan2(Math.cos(obliquity) * Math.sin(eclip_long), Math.cos(eclip_long));
double decl = Math.asin(Math.sin(obliquity) * Math.sin(eclip_long));
double sidereal = SIDEREAL_COEFFICIENT_1 + SIDEREAL_COEFFICIENT_2 * daynum + rlon;
double hour_ang = sidereal - rasc;
double elevation = Math.asin(Math.sin(decl) * Math.sin(rlat) + Math.cos(decl) * Math.cos(rlat) * Math.cos(hour_ang));
//Local azimuth of the sun
double azimuth = Math.atan2(-Math.cos(decl) * Math.cos(rlat) * Math.sin(hour_ang), Math.sin(decl) - Math.sin(rlat) * Math.sin(elevation));
azimuth = into_range(Math.toDegrees(azimuth), 0, 360);
elevation = into_range(Math.toDegrees(elevation), -180, 180);
// 其他操作
}
private static double into_range(double value, double min, double max) {
double range = max - min;
return ((value - min) % range + range) % range + min;
}
}
```
这样,您可以在计算方位角和仰角时直接使用这些常量,使代码更加易读和易于维护。