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wkurtosis

PURPOSE

Computes sample kurtosis

SYNOPSIS

k = wkurtosis(X,dim)

DESCRIPTION

``` WKURTOSIS Computes sample kurtosis

CALL:  k = wkurtosis(X,dim);

k = sample kurtosis (fourth central moment divided by squared second)
X = data vector or matrix
dim = dimension to sum across. (default 1'st non-singleton
dimension of X)

Example:
R=wgumbrnd(2,2,100,2);
wkurtosis(R)

CROSS-REFERENCE INFORMATION

This function calls:
 error Display message and abort function. mean Average or mean value.
This function is called by:
 Chapter2 % CHAPTER2 Modelling random loads and stochastic waves dat2tr Estimate transformation, g, from data.

SOURCE CODE

```001 function k = wkurtosis(X,dim)
002 %WKURTOSIS Computes sample kurtosis
003 %
004 % CALL:  k = wkurtosis(X,dim);
005 %
006 %        k = sample kurtosis (fourth central moment divided by squared second)
007 %        X = data vector or matrix
008 %      dim = dimension to sum across. (default 1'st non-singleton
009 %                                              dimension of X)
010 %
011 % Example:
012 %   R=wgumbrnd(2,2,100,2);
013 %   wkurtosis(R)
014 %
016
017 % Tested on: Matlab 5.3
018 % History:
019 % revised pab 24.10.2000
020 % - made it more general: accepts any size of X
021 % - added dim, nargchk
023
024 error(nargchk(1,2,nargin))
025 sz = size(X);
026 if nargin<2|isempty(dim)
027   % Use 1'st non-singleton dimension or dimension 1
028   dim = min(find(sz~=1));
029   if isempty(dim), dim = 1; end
030 end
031 rsz = ones(size(sz)); rsz(dim)=sz(dim);
032 mu  = mean(X);
033 mu  = repmat(mu,rsz);
034 k   = mean((X-mu).^4,dim)./mean((X-mu).^2,dim).^2;
035
036
037
038
039
040
041
042```

Mathematical Statistics
Centre for Mathematical Sciences
Lund University with Lund Institute of Technology

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