Hi, I have a vector 'A' of length 'n', whose values change with time. 'A' gives the change from a baseline 'B'. I calculate a signal as the distance A from the average of B, i.e., If 'B' is my baseline, then the signal at a time 't' due to A(t) would be given by S=(1/n)*(Ʃ1Ai -<B> - Ʃ2Ai -<B>), i=1 to n. 'A' is divided into two groups of elements whose values are higher than their previous values and those whose values are lower. I define noise as the standard deviation of S. Given this, how do I define the signal-to-noise ratio of A? I found different ways of calculating the SNR in different contexts, but am not very clear as to which one to use in this context. Thanks in advance for any suggestions/help.