Matching factor functions to describe similarity of two vectors. This function may be useful to match an estimated mass spectrum against mass spectra of known compounds, in order to identify the compound represented by the estimated mass spectrum.
matchFactor(u, s, type="dot")numeric between 0 and 1 representing the matching factor; vectors
that are more similar have a larger matching factor. Note that if both
u and s are all zero, we let the matching factor be 1; if one and
only one of u and s are all zero, we let the matching
factor be 0.
numeric vector of length n
numeric vector of length n
character vector describing the matching factor function
to apply; the choices are "dot" for the normalized dot
product or "euclid" for the normalized
euclidean distance.
Katharine M. Mullen
Alfassi ZB. On the normalization of a mass spectrum for comparison of two spectra. Journal of the American Society for Mass Spectrometry 2004; 15:385-387.
Stein SE, Scott DR. Optimization and testing of mass spectral library search algorithms for compound identication. Journal of the American Society for Mass Spectrometry 1994; 5:859-866.
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