// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) 2001 - INRIA - Carlos Klimann
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt
//


function [v]=mvvacov(x)
    //
    //This    function    computes    v,   the    matrix    of
    //variance-covariance of the "tableau" x (x is a numerical
    //matrix nxp)  who gives  the values of  p variables for n
    //individuals:   the    (i,j)   coefficient   of    v   is
    //v(i,j)=E(xi-xibar)(xj-xjbar),  where   E  is  the  first
    //moment of a variable, xi  is the i-th variable and xibar
    //the mean of the xi variable.
    //
    //References: Saporta, Gilbert, Probabilites,  Analyse des
    //Donnees et Statistique, Editions Technip, Paris, 1990.
    //Mardia,  K.V., Kent,  J.T. &  Bibby,  J.M., Multivariate
    //Analysis, Academic Press, 1979.
    //
    //
    warnobsolete("cov", "6.0.0");
    [lhs,rhs]=argn(0)
    if rhs<>1 then error(msprintf(gettext("%s: Wrong number of input argument: %d expected.\n"),"mvvacov",1)), end
    if x==[] then s=%nan, return, end
    [n p]=size(x);
    fact=1/n
    v = fact * ((x'*x) - fact * ( (ones(1,n)*x)' * (ones(1,n)*x)))
endfunction