You might want something like this:
value = 0.8;
occ_points = [0.2, 0.5, 0.7, 1.3];
t = 0:0.01:2;
y = value * ones(size(t));
for ii = 1:numel(occ_points)-1
start_p = find(t > occ_points(ii), 1, 'first');
end_p = find(t <= occ_points(ii+1),1,'last');
y(start_p:end_p) = y(start_p:end_p) * (-1)^ii;
end
plot(t,y)
