PARTIAL LEAST-SQUARES METHODS FOR SPECTRAL ANALYSES .1. RELATION TO OTHER QUANTITATIVE CALIBRATION METHODS AND THE EXTRACTION OF QUALITATIVE INFORMATION
PARTIAL LEAST-SQUARES METHODS FOR SPECTRAL ANALYSES .1. RELATION TO OTHER QUANTITATIVE CALIBRATION METHODS AND THE EXTRACTION OF QUALITATIVE INFORMATION
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DOI：
10.1021/ac00162a020
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发表时间：
1988-06-01
影响因子：
7.4
通讯作者：
THOMAS, EV
中科院分区：
文献类型：
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作者：
HAALAND, DM;THOMAS, EV
偏最小二乘（PLS）光谱分析方法与经典最小二乘（CLS）、逆最小二乘（ILS）、主成分回归（PCR）等多元校正方法有着密切的联系，这些方法常用于光谱定量分析。介绍了一次分析一种化学成分的PLS方法，并说明了算法中各步骤的依据。PLS校准被证明是由一系列简化的CLS和ILS步骤。这种对PLS算法的详细理解有助于确定如何从PLS算法的中间步骤中获得化学上可解释的定性光谱信息。这些方法提取定性信息的演示使用模拟光谱数据。从PLS分析中直接获得的定性信息上级从PCR中获得的定性信息，但不如CLS分析过程中产生的定性信息完整。提出了为偏最小二乘模型和PCR模型选择最佳加载向量数量的方法，以便优化模型，同时减少过度拟合校准数据的可能性。离群值检测和方法来评估从不同的校准方法应用到相同的光谱数据所获得的结果的统计意义进行了讨论。
Partial least-squares (PLS) methods for spectral analyses are related to other multivariate calibration methods such as classical least-squares (CLS), Inverse least-squares (ILS), and principal component regression (PCR) methods which have been used often In quantitative spectral analyses. The PLS method which analyzes one chemical component at a time Is presented, and the basis for each step In the algorithm Is explained. PLS calibration Is shown to be composed of a series of simplified CLS and ILS steps. This detailed un-derstanding of the PLS algorithm has helped to Identify how chemically interpretable qualitative spectral information can be obtained from the Intermediate steps of the PLS algorithm. These methods for extracting qualitative Information are demonstrated by use of simulated spectral data. The qualitative Information directly available from the PLS analysis Is superior to that obtained from PCR but Is not as complete as that which can be generated during CLS analyses. Methods are presented for selecting optimal numbers of loading vectors for both the PLS and PCR models In order to optimize the model while simultaneously reducing the potential for over-fitting the calibration data. Outlier detection and methods to evaluate the statistical significance of results obtained from the different calibration methods applied to the same spectral data are also discussed.