In a book i have there's an exercise that want to find the output of a system for a given signal
system: $ 2y(n)=2x(n)+x(n+1)+x(n-1) $
input : $ Χ=[\underline1, -1, 2, 0, -2, 0, 1 ]$
$Χ1=Χ[0] $
What represent's the underlined value?
$\begingroup$
$\endgroup$
3
asked Jun 17, 2014 at 22:35
-
1$\begingroup$ Just out of curiosity: which book are you referring to? (because I've never seen this notation) $\endgroup$– Matt L.Commented Jun 18, 2014 at 8:46
-
$\begingroup$ it's an internal book from my uni. $\endgroup$– Giannis FoulidisCommented Jun 18, 2014 at 20:00
-
$\begingroup$ Very interesting concept. $\endgroup$– jojeck ♦Commented Jun 28, 2014 at 18:52
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
An arrow or an underline is used to indicate the value at $n=0$. Example,
$$y(n) = \begin{array}{ccccc}[&9 &8 &\underline7 &6 &5 &]\end{array}$$ means that, $$\begin{array}{ccccc}&y(-2) = 9, &y(-1) =8, &y(0)=7, &y(1) = 6 &\mathrm{and} &y(2) =5\end{array}$$
In your case, it says that $$\begin{array}{ccccc}&X(0) = 1, &X(1) =-1, &X(2)=2, &\ldots\end{array}$$
Note: No underline or arrow is equivalent to underlining the first value.
