The researchers also should reduce the influence of irrelevant variables in measurement to guarantee the external validity of processing.

控制具体测量过程中的无关变量的影响，保证统计处理的外部效度。

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Every principle component is the linear combination of the original variables and is irrelevant to each other. The spectra data can be stored and dealt with computer by reducing…

每一个主成分都是原始变量的线性组合，主成分之间互为正交关系，在剔除冗余信息的同时，通过主成分分析的降维，解决光谱数据的存储和处理问题。

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