1.函数实现
0)打印数组
/// <summary>
/// 打印数组
/// </summary>
/// <param name="arr">数组</param>
/// <param name="numberPerLine">每行打印元素数量</param>
/// <param name="digitAfterDot">小数点后保留位数</param>
private static void PrintArray(double[] arr, int numberPerLine = 7, int digitAfterDot = 2)
{
//设定小数点后保留位数(函数ToString()的参数)
string format = "#0.";
while (true)
{
if (digitAfterDot <= 0) break;
format += '0';
digitAfterDot--;
}
//打印数组
for (int i = 0; i < (arr.Length - 1) / numberPerLine + 1; i++)
{
for (int j = 0; j < numberPerLine; j++)
{
int index = i * numberPerLine + j;
if (index < arr.Length)
{
Console.Write(arr[index].ToString(format) + "\t");
}
}
Console.WriteLine();
}
}
1)算术平均数:(x1+x2+...+xn)/n
/// <summary>
/// 计算算数平均数:(x1+x2+...+xn)/n
/// </summary>
/// <param name="arr">数组</param>
/// <returns>算术平均数</returns>
private static double ArithmeticMean(double[] arr)
{
double result = 0;
foreach (double num in arr)
{
result += num;
}
return result / arr.Length;
}
2)几何平均数:(x1*x2*...*xn)^(1/n)
/// <summary>
/// 几何平均数:(x1*x2*...*xn)^(1/n)
/// </summary>
/// <param name="arr">数组</param>
/// <returns>几何平均数</returns>
private static double GeometricMean(double[] arr)
{
double result = 1;
foreach (double num in arr)
{
result *= Math.Pow(num, 1.0 / arr.Length);
}
return result;
}
3)调和平均数:n/((1/x1)+(1/x2)+...+(1/xn))
/// <summary>
/// 调和平均数:n/((1/x1)+(1/x2)+...+(1/xn))
/// </summary>
/// <param name="arr">数组</param>
/// <returns>调和平均数</returns>
private static double HarmonicMean(double[] arr)
{
double temp = 0;
foreach (double num in arr)
{
temp += (1.0 / num);
}
return arr.Length / temp;
}
4)平方平均数:((x1*x1+x2*x2+...+xn*xn)/n)^(1/2)
/// <summary>
/// 平方平均数:((x1*x1+x2*x2+...+xn*xn)/n)^(1/2)
/// </summary>
/// <param name="arr">数组</param>
/// <returns>平方平均数</returns>
private static double RootMeanSquare(double[] arr)
{
double temp = 0;
foreach (double num in arr)
{
temp += (num * num);
}
return Math.Sqrt(temp / arr.Length);
}
5)中位数
/// <summary>
/// 计算中位数
/// </summary>
/// <param name="arr">数组</param>
/// <returns></returns>
private static double Median(double[] arr)
{
//为了不修改arr值,对数组的计算和修改在tempArr数组中进行
double[] tempArr = new double[arr.Length];
arr.CopyTo(tempArr, 0);
//对数组进行排序
double temp;
for (int i = 0; i < tempArr.Length; i++)
{
for (int j = i; j < tempArr.Length; j++)
{
if (tempArr[i] > tempArr[j])
{
temp = tempArr[i];
tempArr[i] = tempArr[j];
tempArr[j] = temp;
}
}
}
//针对数组元素的奇偶分类讨论
if (tempArr.Length % 2 != 0)
{
return tempArr[arr.Length / 2 + 1];
}
else
{
return (tempArr[tempArr.Length / 2] +
tempArr[tempArr.Length / 2 + 1]) / 2.0;
}
}
2.Main函数调用
static void Main(string[] args)
{
//一个数组
double[] arr = new double[]
{
3, 2, 7, 4, 8, 8, 5,
5, 6, 5, 1, 8, 4, 9
};
//打印数组
PrintArray(arr);
//调和平均数≤几何平均数≤算术平均数≤平方平均数
Console.WriteLine("算术平均数:" + ArithmeticMean(arr).ToString("#0.000"));
Console.WriteLine("几何平均数:" + GeometricMean(arr).ToString("#0.000"));
Console.WriteLine("调和平均数:" + HarmonicMean(arr).ToString("#0.000"));
Console.WriteLine("平方平均数:" + RootMeanSquare(arr).ToString("#0.000"));
Console.WriteLine("中位数:" + Median(arr).ToString("#0.000"));
Console.ReadLine();
}
3.运行示例