如何在while循环中从平均值计算中排除负数

Question

我有一个程序，接受用户输入，并计算最大，最小和平均。当用户输入任何负数时，程序将关闭。如何从平均值计算中排除负数？这是我到目前为止所拥有的。

    // variable
    double n = 1;
    double ave = 0;
    double sum = 0;
    double max = Double.MIN_VALUE; 
    double min = Double.MAX_VALUE ;
    int count = 0;
    double neg;

//creat scanner object
 Scanner input = new Scanner(System.in);


//loop
while (n > 0) { 

System.out.print("Input an income (any negative number to quit): "); 
n = input.nextDouble();

sum = sum + n;
count++;
ave = sum / count;

if(n<0) neg = n;
if(n>max && n >= 0 ) max = n;
if(n<min && n >= 0) min = n;
if(n>0) ave = n; }


   System.out.print(" Average " + ave + "\n Maximum " + max + "\n Minimum " + min);

}

}