[Study of numerical mapping methods for DNA sequences].

The first problem to be solved is to map DNA sequences onto numerical sequences in bio molecular sequence analysis by mathematical, physical and digital signal processing methods. The characters and the adaptability of eight existing mapping methods are analyzed in this paper. A new numerical mapping method based on the probability of bases in the segment DNA sequence is presented. Most of the coding sequences are characterized by 3 - base periodicity. Further more, eight numerical mapping methods are compared and the new method is verified by means of the spectrum analysis of DNA sequence with 3 - base periodicity. The computer simulation results show that the mapping method based complex plane is superior to the other seven methods in reflecting the original information of the bio-molecular sequence and the quality of the obtained power spectra. The identification rate the new method attains is approximately what the complex plane method has achieved.