This is the first of two scripts for looking at the power of frequencies in user definable frequency bands.

The user is asked to specify an analysis region, this region is then split up into a number of epochs. Each epoch is analysed in turn and the power of frequencies within each band in each epoch for each channel are dumped to a data file.

This second script for doing spectral analysis in user definable frequency bands has a slightly different approach than SUDSA1. This script is more applicable to users who have lots of short epochs. There are several different analyses which can be performed and in each case the results may be dumped to a text file. The analysis modes available are:

1. Dominant frequency.
2. Power of dominant frequency.
3. Total power of frequencies in bands.
4. Log power of dominant frequency.
5. Log total power of frequencies in bands.
6. Root mean square amplitude.
7. Cross correlation.

This script identifies peaks in a power spectrum stored in a Spike2 result view.

The highest peak and up to 9 other peaks are marked with cursors and a table of up to 50 peak frequency and power values is written to the log view.

This script requires Spike 2 version 4 or higher.

The coherence of two waveforms is the measure of their similarity in frequency content. Coherence is a function of frequency and ranges from 0 for totally incoherent waveforms to 1.0. This script generates the coherence and provides a menu in which the two channels to be used and the number of frequencies in the result are set. Up to 2048 frequencies may be calculated.

The principles and operation of the script are fully described in a Word document file that is enclosed with the script.

This script generates a waterfall display using the results of power spectrum analysis, the resulting display is valuable for showing changes in spectral content over time. Requires version 3 or later.

This script allows the user to generate a 'gated' power spectrum where the sections of data to include in the result are defined by a TextMark channel. The script also gives the option of overlapping the FFT blocks within each time range. A suitable example data file, Demo.smr, is included in the Data folder of your Spike2 directory.

This script requires Spike2 v6.14 or higher.

Keywords: Gated, overlap, power spectrum, FFT