Talk:Cross-correlation matrix

function corr(..) used in definition is not defined, and there is no (at least i cannot find any) link to its definition in wikipedia.

ie. it reads: >>> For random variables X(s) and X(t) at different points s and t of some space, the correlation function is

  C(s,t) = corr(X(s),X(t))

<<< but no explanation/link/definition of what "corr" is.

this is very important! it makes this page useless.