On Fri, 2008-01-11 at 19:59 +0000, Jamie Bullock wrote: > Krimphoff: > > Irregularity = \sum_{k=2}^{N-1} |a_k - \frac{a_{k-1} + a_k + a_{k+1}} > {3}| > > Jensen: > > Irregularity = \frac{\sum_{k=1}^{N} (a_k - a_{k+1})} {\sum_{k=1}^N > a_k^2} > Where a_k is the amplitude of the kth coefficient in the magnitude spectrum. Jamie -- www.postlude.co.uk