Post-processing options – Multichannel Systems NeuroExplorer User Manual
Page 49
2.3. Post-Processing Options
For the histogram-style analyses, NeuroExplorer has an optional Post-processing analysis step.
You can select post-processing options using Post-processing tab in the Analysis Parameters dialog.
(double-click in the Graph window and select Analysis Parameters menu item):
You can smooth the resulting histogram with Gaussian or Boxcar filters.
The boxcar filter is a filter with equal coefficients. If f[i] is i-th filter coefficient and w is the filter width,
then
f[i] = 1/w for all i
Thus for the filter of width 3, the boxcar filter is
f[-1] = 0.33333, f[0] = 0.33333, f[1] = 0.33333.
and the smoothed histogram sh[i] is calculated as
sh[i] = f[-1]*h[i-1] + f[0]*h[i] + f[1]*h[i+1]
where h[i] is the original histogram.
The Gaussian filter is calculated using the following formula:
f[i] = exp(-i*i/sigma)/norm, i from -2*d to 2*d
where
d = ( (int)w + 1 )/2
sigma = -w * w * 0.25 / log(0.5)
norm = sum of exp( -i * i / sigma), i from -2*d to 2*d
The parameters of the filter are such that the width of the Gaussian curve at half the height equals to
the specified filter width. Please note that for the Gaussian filter, width of the filter (w) can be a non-
integer. For example, w can be 3.5.
See
for more information on NeuroExplorer post-processing
capabilities.
Page 47