我得到java.lang.ArithmeticException錯誤

Question

這是主要方法。試圖計算雙x數學公式，它給我運行代碼的問題。有人可以幫忙嗎？

final int P = Integer.parseInt(args[0]); 
final int Q = Integer.parseInt(args[1]); 
final double H = Double.parseDouble(args[2]); 
final int N = Spiro.numberOfRevolutions(P, Q); 

IPoint2D point = new IPoint2D(0., 0.); 
SimpleDrawing.drawPoint(point); 

for (int i = 1; i <= 360*N; i++) { 
    final int r = P/Q; 
    double radianI = Math.toRadians(i); 
    double x = ((1 - r) * Math.cos(radianI)) + (H * Math.cos(((1- r)/r) * radianI)); 
    double y = ((1 - r) * Math.sin(radianI)) + (H * Math.sin(((1- r)/r) * radianI)); 

    IPoint2D point1 = new IPoint2D(x,y); 
    SimpleDrawing.drawPoint(point1); 
} 

Answer 1

當你這樣做：

final int r = P/Q; 

你需要確保Q是永遠不會爲零，否則這將是ArithmeticException

Answer 2

如果P小於Q（或Q是0將立即拋出ArithmeticException）

final int r = P/Q; 

r將具有值0。然後，您可以通過r=0

double x = ((1 - r) * Math.cos(radianI)) + (H * Math.cos(((1- r)/r) * radianI)); 

投擲ArithmeticException劃分。