Next: A wavelet Up: No Title Previous: Introduction . Figure: Data characterization using wavelets. The time axis is common to the raw data and the wavelet map (background), for which the vertical axis is analogous to an inverse frequency (Section 10). The Mexican hat wavelet (Section 3) used for the background wavelet map (Section 5) measures the magnitudes of local maxima (blue-grey shades) and minima (yellow/red shades) as a function of time and duration. ...