find zeros, local maximums, loacal minimums

3 functions: [z isrise]=find_zeros(s); mn=loacal_minimums(s); mx=loacal_maximums(s);

http://simulations.narod.ru/
vectorized codes to find zeros, local maximums, loacal minimums. Zero is when signal change sign. Maximum is element that more then previouse and more then next. Minimum is element that less then previouse and less then next. Run zz_test.m to test functions.