概率权重矩法估计P－Ⅲ型分布参数用表的近似表达式

A pproximate Expressions for PWM Method in Estimating the P-Ⅲ Distributed Parameters

以概率权重矩法估计Ｐ－Ⅲ型分布参数需用专门数表，实用上十分不便。本文对该数表建立了近似表达式，从而大大简化了查表和内插运算。验算表明，近似表达式能满足工程运算的精度要求。

A specific table is necessary for Probability Weighted Moments(PWM)to estimate thePearson TypeⅢ distributed parameters.However,the computational procedure with the help of such a table isvery inconvenient in practice. Therefore,some approximate expressions are presented in this paper to simplify thetable look-up and interpolating computation. The verification of the approximate expressions shows that theyhave reached the necessary accuracy for engineering practice.