摘要
本文在P-Ⅲ型(皮尔逊Ⅲ型)分布次序统计量期望值数值积分计算成果的基础上,利用次序统计量不同样本长度期望值之间的关系,探讨了计算任意样本长度(n≤1 000)、任意偏态系数(Cs∈[0,10.0])的P-Ⅲ型分布次序统计量期望值EX(m)及其频率F(EX(m))(俗称无偏绘点位置)的快速高精度计算框架。数值计算表明该计算框架是可行的,也改变了国内外此前一直通过拟合经验公式来近似P-Ⅲ型分布函数次序统计量期望值的频率F(EX(m))的做法。
Based on the numerical integral of expected value of order statistics with Pearson Type-Ⅲ distribution, the relationships between expected values for different sizes of sample is used to investigate the high speed and high accuracy computation framework for order statistic expectation EX(m) and its frequency F(the unbiased plotting position) of this kind of hydrological probability statistics with arbitrary size of sample (n 〈 1 000) and arbitrary, skewness coefficient. By using this proposed method the expected frequency F is not necessary to be obtained from traditional fitting for empirical formula.
出处
《水利学报》
EI
CSCD
北大核心
2006年第8期938-944,共7页
Journal of Hydraulic Engineering
基金
水利部948项目(200407)
水利部重大科研项目"水库设计运用专题研究项目"
关键词
水文概率
次序统计量
期望值
无偏绘点位置
皮尔逊Ⅲ型分布
hydrological probability
order statistics
expected value
unbiased plotting position
Pearson type-Ⅲ distribution