Wavelet Toolbox

Scale and Frequency

Notice that the scales in the coefficients plot (shown as y-axis labels) run from 1 to 31. Recall that the higher scales correspond to the most "stretched" wavelets. The more stretched the wavelet, the longer the portion of the signal with which it is being compared, and thus the coarser the signal features being measured by the wavelet coefficients.

Thus, there is a correspondence between wavelet scales and frequency as revealed by wavelet analysis:

• Low scale a Compressed wavelet Rapidly changing details High frequency .
• High scale a Stretched wavelet Slowly changing, coarse features Low frequency .

Five Easy Steps to a Continuous Wavelet Transform

The Scale of Nature