gusucode.com > S变换的matlab源码程序 > code/stest.m
% the s-tranform test script len = 128; freq = 5; t = 0:len-1; % CREATE CROSS CHIRP TIME SERIES cross_chirp = cos(2*pi*(10+t/7).*t/len) + cos(2*pi*(len/2.8-t/6.0).*t/len); % CREATE MODULATED SIN FUNCTION TIME SERIES mod_freq=4*cos(2*pi*t/len)+len/5; sin_of_sin = cos(2*pi*mod_freq.*t/len); % CREATE the Distinct sinusoids example midfreq = 20; lowfreq = 5; highfreq = 45; distinct = cos(2*pi*midfreq.*t/len); distinct(1:len/2) = cos(2*pi*lowfreq.*t(1:len/2)/len); distinct(20:30) = cos(2*pi*highfreq .*t(20:30)/len); % CREATE the chirp example chirp = cos(2*pi*(10+t/7).*t/len); [st_matrix,st_times,st_frequencies] = st(sin_of_sin); [st_matrix_chirp,st_times,st_frequencies] = st(chirp); [st_matrix_chirps,st_times,st_frequencies] = st(cross_chirp); [st_matrix_distinct,st_times,st_frequencies] = st(distinct); contourf(st_times,st_frequencies,abs(st_matrix_chirps)); %mesh(abs(st_matrix_chirp));