Fig 1.
Examples of functions with different asymmetry used in the enriched dictionary.
Fig 2.
At the very top: simulated signal. Below: time-frequency-energy representations of the simulated signal obtained by: A—asymmetric dictionary and B—Gabor dictionary; time-frequency-amplitude representations obtained by: C—asymmetric dictionary and D—Gabor dictionary. Crosses mark the centers of the atoms.
Fig 3.
The decomposition of the function shown in the upper panels: on the left the representation by means of the enriched dictionary, on the right by means of the Gabor dictionary. In the case of Gabor dictionary, four functions are needed to account for 97.7% of energy, in case of the enriched dictionary one function alone is sufficient. Panels at the bottom: amplitude representation for enriched dictionary (left) and Gabor dictionary (right). Crosses mark the centers of the atoms.
Fig 4.
Time-frequency distributions obtained by: A—windowed Fourier transform (spectrogram), B—Rihaczek transform, C—Morlet wavelets, D—Wigner de Ville transform, E—MP with the enriched dictionary, F—MP with the Gabor dictionary.
Components of simulated signal consisting of asymmetric waveform of frequency 15 Hz and two spindles of frequencies 12 Hz and 10 Hz are shown at the very top of the picture. On the horizontal axis time, on the vertical axis frequency in Hz. The colors represent: for four upper panels energy and for two lowest panels amplitude (red the strongest, dark blue the weakest).
Fig 5.
The decomposition of the TOAE signal shown at the very top; obtained by the enriched dictionary (on the left) and by Gabor dictionary (on the right). Below the time-frequency-amplitude maps, at the bottom the first five (strongest) atoms of the decomposition. The maxima of amplitudes of the first five atoms are marked by crosses.
Table 1.
Parameters of TOAE structures provided by enriched dictionary.
Table 2.
Parameters of TOAE structures provided by standard Gabor dictionary.
Fig 6.
The decomposition of the SSVEP signal recorded at electrode O2 (shown at the very top) obtained by the enriched dictionary (on the left) and by Gabor dictionary (on the right). Below: time-frequency-amplitude maps, at the bottom the first five atoms of the decomposition. In Table 3, parameters (frequency, amplitude, time occurrence and time span) describing the first five atoms are shown. In the time-frequency map harmonics at 30 Hz is not shown in order to make the figure more compact.
Table 3.
Parameters of SSVEP structures provided by both dictionaries in O2 channel.
Table 4.
Parameters of SSVEP structures provided by both dictionaries in P4 channel.
Fig 7.
The decomposition of the SSVEP signal recorded at electrode P4 (shown at the very top) obtained by the enriched dictionary (on the left) and by Gabor dictionary (ont right). Below: time-frequency-amplitude maps, at the bottom the first five atoms of the decomposition. In Table 4, parameters (frequency, amplitude, time occurrence and time span) describing the first five atoms are shown. In the time-frequency map harmonics at 30 Hz is not shown in order to make the figure more compact.