This example shows how to perform time-frequency analysis using the continuous wavelet transform (CWT). Continuous wavelet analysis provides a time-scale/time-frequency analysis of signals and images. The Wavelet Toolbox™ software has both command line and interactive functionality to support continuous wavelet analysis of 1-D signals.
Construct a signal consisting of two sinusoids with frequencies of 100 and 50 Hz. The support of the two sinusoids is disjoint. The 100-Hz sine wave begins at t = 0 and has a duration of 1 second. The 50-Hz sinusoid begins at three seconds and has a duration of two seconds.
Fs = 1000; t = linspace(0,5,5e3); x = cos(2*pi*100*t).*(t<1)+cos(2*pi*50*t).*(3<t)+0.3*randn(size(t));
Obtain the CWT and plot its scalogram