one of the things i remember that impressed me about my first exposure to Oppenheim & Schafer was the formal and rigorous use of math. one thing they did early on was to adopt a different notation, $x[n]$ for discrete-time signals that was different than for continuous-time $x(t)$. they may have been influenced by the C language notation for arrays, x[n]
, i dunno.
in the days of old (the 70s), there were DSP texts that used the standard math notation for discrete sequences (i.e. $x_n$), but the problem was when we would get a vector of signals in continuous-time, $x_k(t)$. if sampled, $x_k(nT)$, how was that notation nicely converted to a sequence. $x_{k,n}$ was not good and $x_k(n)$ was also not good.
should we encourage, expect, edit to maintain the usage of this notation?
x
at the instantt
regardless thatt=dt n
...... You only need to properly extend the $\delta$ framework. $\endgroup$ – Brethlosze Dec 23 '16 at 2:23