s =；

BJ=sym (zero (size)); The% array BJ is used to store labels.

Big = 3; % defines the variance greater than 3 as "much larger" and can be modified as needed.

For ii=2: length (seconds)-1

If s (ii)-big > S(ii- 1) and amps (ii)-big > S(ii+ 1)

BJ ii) =' A

BJ(ii+ 1)= ' B '；

BJ(ii+2)= ' C '；

end

end

BJ

Final output

BJ=[ 0，A，B，C，0，0，A，B，C，0]