null adj. 1.无效力的,无束缚力的。 2.无效的,无用的,无益的;无价值的。 3.没特征[个性]的,没表情的。 4.〔罕用语〕不存在的,没有的;零(位)的;空的。 n. 【数学】零,零位;空;【无线电】零讯号,微弱讯号。 a null indicator 零示器;零位指示器。 the null method 衡消法。 null and void 【律】无效;失效(This check is null and void. 本支票无效)。 vt. 使无效。
correlation n. 相互关系,相关(性);对比;交互作用;【数学】对射,异射。 correlation index 关联指数。 correlation mineral 对比矿物。
The distribution and structure of the allelic polymorphism data are analyzed and it is pointed out that the distribution of allelic polymorphism data reveals the characteristic of closed data ( also named as compositional data or data of constant sum ) it is interpreted that the correlation structure of the allelic polymorphism data contains null correlations introduced by " closure " and the statistical distribution of the data is not normal because of its constant row sum , which resulted in great difficulties in analyzing the data with traditional multiple linear statistical methods such as principal component analysis , factor analysis , cluster analysis and canonical correlation analysis 摘要长期以来,对于多维基因多态性数据的多元统计分析,如计算遗传距离时所用的聚类分析、分析群体遗传结构时所用的主成分分析、因子分析和典型相关分析等,一直应用为无约束条件数据而设计的经典多元线性分析方法,并没有注意基因多态性数据的“闭合效应”所带来的问题。