Computerized Searching of Inverted Files F. E. Lytle Department of Chemistry, Purdue University, Lafayette, Ind. 47907
A computerized inverted file technique has been developed that will search large collections of analytical data. The program, written in Fortran, is designed for use with small laboratory computers having papertape, card, or disk input. Data compression is utilized to its fullest extent reducing both input time and storage requirements. The most important advantage is that it easily lends itself to automation and can allow “on-line” searches of collections of analytical data.
INFRARED SPECTRAL interpretation has been widely used as an analytical tool for both research and quality control applications. These absorption bands can indicate various functional groups and may ultimately lead to an identification of a sample’s structure. The analysis is, however, only completely certain when a point-to-point spectral comparison has been made with a known sample. To this end an indexed collection of spectra is invaluable. As the volume of cataloged data has grown, various attempts have been made toward rapid retrieval of specific reference curves. Kenyon (Z), in his excellent review article, discusses five classes of indexes used for such data retrieval. These classes and some of their characteristics are summarized in Table I. Curry, Read, and Brown ( 2 ) , discuss the same type of indexes and arrive at the conclusion that edge notched cards are probably best for searching small collections of spectra (
