Abstract

A method of comparing two spectra using linear and quadratic regression is described. For every wavelength, the log(1/R) value of the first spectrum is used as x, that of the second as y. The correlation coefficient (r) is used to compute a similarity index which can be used to test for identity. The method has the advantage of comparing whole spectra, rather than only certain peaks, while reducing the data to a single variable. For crystalline solids with different particle sizes, better results are obtained if a quadratic rather than a linear equation is used. This procedure allows the successful identification of isomers and sugars, even when there is considerable variation in particle size.

© 1996 NIR Publications

Quantitative analysis of bayberry juice acidity based on visible and near-infrared spectroscopy

Yongni Shao, Yong He, and Jingyuan Mao
Appl. Opt. 46(25) 6391-6396 (2007)

Single-chip source-free terahertz spectroscope across 0.04–0.99 THz: combining sub-wavelength near-field sensing and regression analysis

Xue Wu and Kaushik Sengupta
Opt. Express 26(6) 7163-7175 (2018)

Near infrared spectroscopic analysis of single malt Scotch whisky on an optofluidic chip

Praveen C. Ashok, Bavishna B. Praveen, and K. Dholakia
Opt. Express 19(23) 22982-22992 (2011)

Spectroscopic near-field microscopy using frequency combs in the mid-infrared

Markus Brehm, Albert Schliesser, and Fritz Keilmann
Opt. Express 14(23) 11222-11233 (2006)

Optical system for tablet variety discrimination using visible/near-infrared spectroscopy

Yongni Shao, Yong He, and Xingyue Hu
Appl. Opt. 46(34) 8379-8384 (2007)