How to calculate variance coefficient

I would like to analise segmented microelectrode recording data. I found an article which describe artifat removal. For that I need to calculate the variance of autocovariance for each epochs. It provides the formula, but I don't really know which function stands for it in matlab. The formula is on the picture below.

[Mathieu NOE]

help var

var Variance.

For vectors, Y = var(X) returns the variance of the values in X. For

matrices, Y is a row vector containing the variance of each column of

X. For N-D arrays, var operates along the first non-singleton

dimension of X.

[Bence Laczó]

I have checked the help, but the problem is that I don't know whether the formula used by the variance command is the same that I have posted?

[Mathieu NOE]

hello

you can edit the function (edit var) and see / check the code