title: On relationship of Z-curve and Fourier approaches for DNA coding sequence classification.
abstract: Z-curve features are one of the popular features used in exon/intron classification. We showed that although both Z-curve and Fourier approaches are based on detecting 3-periodicity in coding regions, there are significant differences in their spectral formulation. From the spectral formulation of the Z-curve, we obtained three modified sequences that characterize different biological properties. Spectral analysis on the modified sequences showed a much more prominent 3-periodicity peak in coding regions than the Fourier approach. For long sequences, prominent peaks at 2Pi/3 are observed at coding regions, whereas for short sequences, clearly discernible peaks are still visible. Better classification can be obtained using spectral features derived from the modified sequences.
authors.affiliation: Centre for Multimedia Signal Processing, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. ennflaw@polyu.edu.hk
authors.forename: Ngai-Fong
authors.initials: NF
authors.lastname: Law
authors.forename: Kin-On
authors.initials: KO
authors.lastname: Cheng
authors.forename: Wan-Chi
authors.initials: WC
authors.lastname: Siu