'xcorr' function in matlab not working for zero signal
the xcorr function is defined as
$$R_{xy}(m)=
\left\{
 \begin{array}{ll}
  \sum\limits_{n=0}^{N-m-1}x_{n+m}y^*_n  &amp; \mbox{if } m \geq 0 \\
  R^*_{yx}(-m)&amp; \mbox{if } m &lt; 0
 \end{array}
\right.$$
The output is given as $$c(m)=R_{xy}(m-N)$$ where N is the length of the signal by the above definition the output for zero signal is zero