Java 数组元素不工作的算术公式
这是一个使用Buffons针模拟来估计pi值的程序。 我在这里遇到的问题是,在方法calcPi中,pi数组的元素在for循环中的算术公式之后一直显示为0。我查过了,计数器和审判台都在工作。。帮忙Java 数组元素不工作的算术公式,java,math,for-loop,methods,random,Java,Math,For Loop,Methods,Random,这是一个使用Buffons针模拟来估计pi值的程序。 我在这里遇到的问题是,在方法calcPi中,pi数组的元素在for循环中的算术公式之后一直显示为0。我查过了,计数器和审判台都在工作。。帮忙 import java.util.Scanner; public class Darts { public static int trials() //User Inputs number of trials { int input; Scanner in
import java.util.Scanner;
public class Darts
{
public static int trials() //User Inputs number of trials
{
int input;
Scanner in = new Scanner(System.in);
System.out.print("How many darts/trials? ");
input = in.nextInt();
return input;
}
public static double [] randomX(int trial) // Randomly generates numbers for the x coordinate on the amounts of trials
{
double [] randNumArrayX = new double[trial];
for(int i = 0; i < trial; i++)
{
randNumArrayX[i] = Math.random();
}
return randNumArrayX;
}
public static double [] randomY(int trial) // Randomly generates numbers forthe y coordinate on the amounts of trials
{
double [] randNumArrayY = new double[trial];
for(int i = 0; i < trial; i++)
{
randNumArrayY[i] = Math.random();
}
return randNumArrayY;
}
public static int [] dartBoard(double [] randx, double [] randy) // determines whether the dark hit the board or not
{
int [] hitMiss = new int[randx.length];
int [] trials = new int[randx.length];
for(int i = 0; i < randx.length; i++)
{
if( Math.pow(randx[i] , 2) + Math.pow(randy[i] , 2) <= 1)
{
hitMiss[i] = 1;
}
else
{
hitMiss[i] = 0;
}
}
return hitMiss;
}
public static double [] calcPi(int [] h) // Calculates pi using randomly generated numbers
{
int hitCounter = 0;
double [] pi = new double[h.length];
for(int i = 0; i < h.length; i++)
{
if(h[i] == 1)
{
hitCounter++;
}
pi[i] = 4*(hitCounter/(i + 1));
}
return pi;
}
public static void print(double [] pi) // prints results
{
for(int i = 0; i < 10; i++)
{
System.out.printf("%-7s%2d%-8s%-10.6f%n", "Trial [", i, "]: pi = ", pi[i]);
}
System.out.println("\t .....");
System.out.printf("%-17s%-10.6f%n", "Estimate of pi = ", pi[pi.length -1]);
}
public static void main(String [] args) // main method
{
int t = trials();
double [] x = new double[t];
double [] y = new double[t];
int [] h = new int[t];
double [] p = new double[t];
x = randomX(t);
y = randomY(t);
h = dartBoard( x , y );
p = calcPi( h );
print(p);
}
}
import java.util.Scanner;
公共级飞镖
{
public static int trials()//用户输入试用次数
{
int输入;
扫描仪输入=新扫描仪(系统输入);
系统输出打印(“多少省道/试验?”);
input=in.nextInt();
返回输入;
}
public static double[]randomX(int-trial)//根据试验量随机生成x坐标的数字
{
double[]RandNumarayx=新的double[试用版];
for(int i=0;i 如果(Math.pow(randx[i],2)+Math.pow(randy[i],2)你的问题可能是这一行:
pi[i]=4*(命中计数器/(i+1));
您正在进行整数除法,由于hitcounter
始终低于i
它将始终返回0
试试这个
pi[i]=4*(命中计数器/(i+1d));
注意1d
这将强制进行双除法。这可能是由于整数除法
试一试
pi[i]=4*(命中计数器/(i+1.0));
Java中的1.0
literal是double类型。基本上,从那里开始
此表达式中的所有其他值也将提升为双精度