%% (Internal) Detect zero-crosses in a signal
%
% Returns the index of the input vector in which the first zero crossing is located.
%
% index = myzerocros(x)
%
% Arguments:
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% + x: signal
%
% Output:
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% + index: indexes where zero-crosses occurs.
%
% Example:
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% Author: Mariano Llamedo Soria llamedom@electron.frba.utn.edu.ar
% Version: 0.1 beta
% Last update: 14/5/2014
% Birthdate : 21/4/2015
% Copyright 2008-2015
%
function index = myzerocros(x)
sx = sign(x);
diffsx = diff(sx);
diffsx = [diffsx(1); diffsx];
index = find( diffsx ~= 0);