function [K] = kurtosis(x)%KURTOSIS: Compute the kurtosis of a time series or%          of a multichannel series%%  [K] = kurtosis(x);%%  IN   x:      data (vector or matrix)%%  OUT  K:      Kurtosis%%%  Kurtosis is defined as K = E(x^4)/ (E(x^2))^2;%%    K = 3 for a Gaussian series %%  There is a different definiton k' = K-3%%    k' = 0 for a Gaussian series%%  k' is called the Kurtosis Excess. This matlab %  function computes K not k'.%%%  Author(s): M.D.Sacchi (sacchi@phys.ualberta.ca)%  Copyright 1988-2005 SeismicLab%  Revision: 1.2  Date: Ago/2005%%  Signal Analysis and Imaging Group (SAIG)%  Department of Physics, UofA% N = ndims(x);[n1,n2]=size(x); Ns = n1*n2; if N==1;   sum1 = sum(x.^4)/Ns;  sum2 = (sum(x.^2)/Ns)^2; end;  if N==2;   sum1 = sum(sum(x.^4)/Ns);  sum2 = (sum(sum(x.^2))/Ns)^2; end; K = sum1/sum2;