How to separate time series data?

For context, I have 15 seconds worth of data although I only want to analyse the data from 12 seconds to 15 seconds. How do i seperate the final 3 seconds from my time series data?

TIA :)

Answer 1

[Star Strider]

It depends how they are formatted.

Assuming the times are a datetime array —

t = datetime(1,1,1) + seconds(0:0.5:15).';
s = randn(size(t));
T1 = table(t,s)                                         % Data Table

T1 = 31×2 table
             t                  s    
    ____________________    _________

    01-Jan-0001 00:00:00     -0.10358
    01-Jan-0001 00:00:00     -0.73795
    01-Jan-0001 00:00:01    -0.046795
    01-Jan-0001 00:00:01    0.0031687
    01-Jan-0001 00:00:02     -0.73363
    01-Jan-0001 00:00:02       1.5337
    01-Jan-0001 00:00:03       1.3429
    01-Jan-0001 00:00:03     -0.22569
    01-Jan-0001 00:00:04     -0.35433
    01-Jan-0001 00:00:04     -0.72689
    01-Jan-0001 00:00:05      -2.0043
    01-Jan-0001 00:00:05      0.51185
    01-Jan-0001 00:00:06     -0.26662
    01-Jan-0001 00:00:06      0.76956
    01-Jan-0001 00:00:07       1.9912
    01-Jan-0001 00:00:07      0.31162

Lv = second(T1{:,1}) >= 12;                             % Logical Vector

T1e = T1(Lv,:)                                          % Result

T1e = 7×2 table
             t                 s   
    ____________________    _______

    01-Jan-0001 00:00:12     0.2435
    01-Jan-0001 00:00:12    0.65176
    01-Jan-0001 00:00:13    0.37124
    01-Jan-0001 00:00:13     1.0221
    01-Jan-0001 00:00:14    -1.8486
    01-Jan-0001 00:00:14    -0.5345
    01-Jan-0001 00:00:15    0.18867

.