public static string CI(string VarName, string [] Numbers, string Tail, string Statistics, double Significance)
{
//Confidence Interval 置信区间
//Tail为单双尾,Tail = "单尾"，Tail = "双尾"
//Statistics为统计量 "均值" "比例"
int count = 0;
//count用于统计样本个数
StringBuilder result = new StringBuilder();
//result记录反馈结果
BigDecimal Sd = 0;
//Sd为标准差
double Temp = 0;
//Temp用于记录临时数据
BigDecimal BigTemp = 0;
//BigTemp用于记录BigDecimal类型的临时数据
if (Tail == "双尾")
{
Significance = 1 - (1 - Significance) / 2;
// 1 - (1 - 0.95)/2
}
if (Statistics == "均值" || Statistics == "方差")
{
BigDecimal Mean = 0;
BigDecimal Sum = 0;
BigDecimal Sum2 = 0;
foreach (string Num in Numbers)
{
if (double.TryParse(Num, out Temp))
{
Sum += Temp;
Sum2 += (BigDecimal)Temp * (BigDecimal)Temp;
count++;
}
}
if (count <= 1)
{
return("样本数量过少，无法进行参数估计");
}
else
{
Mean = Sum / count;
BigDecimal Variance = (Sum2 / count - Mean * Mean) * count / (count - 1);
Sd = MathV.Sqrt(Variance.ToString()).ToString();
result.Append(StrManipulation.PadLeftX(StrManipulation.VariableNamePolish(VarName), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX(count.ToString(), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish(Mean.ToString()), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish(Sd.ToString()), ' ', 12));
result.Append("\t");
if (Statistics == "均值")
{
if (count >= 30)
{
//大样本
BigTemp = NORMSINV(Significance) * Sd / MathV.Sqrt(count).ToString();
}
else
{
//小样本
BigTemp = TINV(1 - Significance, (count - 1)) * Sd / MathV.Sqrt(count).ToString();
}
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish((Mean - BigTemp).ToString()), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish((Mean + BigTemp).ToString()), ' ', 12));
result.Append("\r\n");
}
else
{
//Statistics == "方差"
BigTemp = (count - 1) * Variance;
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish((BigTemp / Stat.chi2Ua(1 - Significance, count - 1)).ToString()), ' ', 12));
result.Append("\t");
MessageBox.Show(Significance.ToString());
MessageBox.Show(Stat.chi2Ua(Significance, count - 1).ToString());
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish((BigTemp / Stat.chi2Ua(Significance, count - 1)).ToString()), ' ', 12));
result.Append("\r\n");
}
return(result.ToString());
}
}
else if (Statistics == "比例")
{
int OneCounts = 0;
int ZeroCounts = 0;
foreach (string Num in Numbers)
{
if (Num.Trim() == "1")
{
OneCounts++;
}
else if (Num.Trim() == "0")
{
ZeroCounts++;
}
}
if (ZeroCounts + OneCounts == 0)
{
return("样本不存在，无法进行参数估计\r\n");
}
else
{
if (ZeroCounts + OneCounts < 30)
{
result.Append("样本数量较少，进行比例的参数估计可能会不稳定\r\n");
}
BigDecimal Proportion = (BigDecimal)OneCounts / ((BigDecimal)ZeroCounts + (BigDecimal)OneCounts);
count = ZeroCounts + OneCounts;
result.Append(StrManipulation.PadLeftX(StrManipulation.VariableNamePolish(VarName), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX((ZeroCounts + OneCounts).ToString(), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish(Proportion.ToString()), ' ', 12));
result.Append("\t");
BigTemp = Proportion * (1 - Proportion);
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish(MathV.Sqrt(BigTemp.ToString()).ToString()), ' ', 12));
result.Append("\t");
BigTemp = NORMSINV(Significance) * ((BigDecimal)MathV.Sqrt(BigTemp.ToString()).ToString() / (BigDecimal)MathV.Sqrt(count).ToString());
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish((Proportion - BigTemp).ToString()).ToString(), ' ', 12));
result.Append("\t");
result.Append(StrManipulation.PadLeftX(MathV.NumberPolish((Proportion + BigTemp).ToString()).ToString(), ' ', 12));
result.Append("\r\n");
return(result.ToString());
}
}
else
{
return("未知统计量\r\n");
}
}