Try this —
t = linspace(0,25, 500); % Create Data
signal = sum(sin(0.5*rand(5,1)*2*pi*t+rand(5,1)*pi)); % Create Data
zxi = find(diff(sign(signal))); % Indices Of Approximate Zero-Crossings
tlen = numel(t);
for k = 1:numel(zxi)
idxrng = max(1,zxi(k)-2):min(zxi(k)+2,tlen); % Index Range For Interpolation
ti(k) = interp1(signal(idxrng), t(idxrng), 0); % 'Precise' Zero-Crossings
end
for k = 1:numel(ti)-1
tc{k} = t(t>=ti(k) & t<ti(k+1)); % Time Vector Between Zero-Crossings
sigc{k} = interp1(t,signal,tc{k}); % Associated Signal Vector
end
figure
plot(t, signal)
hold on
plot(t(zxi), signal(zxi), 'sr')
hold off
grid
title('Original Signal & Approximate Zero-Crossings')
sps = numel(tc);
for k = 1:sps
subplot(ceil(sps/3),3,k)
plot(tc{k}, sigc{k}, 'LineWidth',1.2)
grid
title(sprintf('Segment #%02d',k))
end
sgtitle('Signal Segments Between Zero-Crossings')
.
