

   LLaaggggeedd DDiiffffeerreenncceess

        diff(x, ...)
        diff.default(x, lag=1, differences=1)

   AArrgguummeennttss::

          x: a numeric vector or matrix containing the values
             to be differenced.

        lag: an integer indicating which lag to use.

   differences: an integer indicating the order of the differ-
             ence.

   VVaalluuee::

        If `x' is a vector of length `n' and `differences=1',
        then the computed result is equal to the successive
        differences `x[(1:n-lag)]-x[(lag:n)]'.  If `difference'
        is larger than one this algorithm is applied recur-
        sively to `x'. Note that the returned value is a vector
        which is shorter than `x'.

        If `x' is a matrix then the difference operations are
        carried out on each column separately.

        `NA''s propagate.

   EExxaammpplleess::

        diff(1:10, 2)
        diff(1:10, 2, 2)

