viSite2_spk
For each spike, it contains the site numbers containing the second largest filtered spike amplitude (s1 in the figure).
JRCLUST keeps two copies of the features, one centered at the peak site (S0.viSite_spk) and another centered at the second peak site (S0.viSite2_spk). This is useful when the peak position shifts between the first and second largest sites due to noise jitters, especially when these two sites contain similar spike amplitudes.
See also: S0, S0.viSite_spk
