// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) ????-2008 - INRIA
//
// 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 t=trace(a)
    // trace - computes the trace of a matrix
    select type(a)
    case 1 then
        [m,n]=size(a)
        if m<>n then
            error(msprintf(gettext("%s: Wrong size for input argument #%d: A square matrix expected.\n"),"trace",1));
        end
        t=sum(diag(a))
    case 2 then
        [m,n]=size(a)
        if m<>n then
            error(msprintf(gettext("%s: Wrong size for input argument #%d: A square matrix expected.\n"),"trace",1));
        end
        t=sum(diag(a))
        //-compat next case retained for list /tlist compatibility
    case 15 then
        if a(1)=="r" then
            [m,n]=size(a)
            if m<>n then
                error(msprintf(gettext("%s: Wrong size for input argument #%d: A square matrix expected.\n"),"trace",1));
            end
            t=sum(diag(a))
        else
            error(msprintf(gettext("%s: Wrong type for input argument #%d.\n"),"trace",1));
        end
    case 16 then
        if a(1)=="r" then
            [m,n]=size(a)
            if m<>n then
                error(msprintf(gettext("%s: Wrong size for input argument #%d: A square matrix expected.\n"),"trace",1));
            end
            t=sum(diag(a))
        else
            error(msprintf(gettext("%s: Wrong type for input argument #%d.\n"),"trace",1));
        end
    case 5 then
        [m,n]=size(a)
        if m<>n then
            error(msprintf(gettext("%s: Wrong size for input argument #%d: A square matrix expected.\n"),"trace",1));
        end
        t=sum(diag(a))
    else
        error(msprintf(gettext("%s: Wrong type for input argument #%d.\n"),"trace",1));
    end
endfunction