www.gusucode.com > wavelet 源码程序 matlab案例代码 > wavelet/cwtftdemo.m
%% Frequency- and Time-Localized Reconstruction from the Continuous Wavelet Transform % Reconstruct a frequency-localized approximation of Kobe earthquake data. % Extract information from the CWT for frequencies in the range of % [0.030, 0.070] Hz. load kobe; %% % Obtain the CWT of the data. [wt,f] = cwt(kobe,1); %% % Reconstruct the earthquake data, adding the signal mean back into the % transformed data. xrec = icwt(wt,f,[0.030 0.070],'SignalMean',mean(kobe)); %% % Plot and compare the original data and the data for frequencies in the % range of [0.030, 0.070] Hz. subplot(211) plot(kobe); grid on; title('Original Data'); subplot(212) plot(xrec); grid on; title('Bandpass Filtered Reconstruction [0.030 0.070] Hz'); %% % You can also use time periods, instead of frequency, with the CWT. % Load the El Nino data and obtain its CWT, specifying the time period in % years. load ninoairdata; [cfs,period] = cwt(nino,years(1/12)); %% % Obtain the inverse CWT for years 2 through 8. xrec = icwt(cfs,period,[years(2) years(8)]); %% % Plot the CWT of the reconstructed data. Note the absence of energy % outside the band of periods from 2 to 8 years. figure; cwt(xrec,years(1/12)); %% % Compare the original data with the reconstructed data for years 2 thorugh % 8. figure; subplot(211) plot(nino); grid on; title('Original Data'); subplot(212) plot(xrec); grid on; title('El Nino Data - Years 2-8');