// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) 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 txt=%p_string(p)
    [m,n]=size(p)
    s=stripblanks(varn(p))
    txt=emptystr(2*m,n)

    for l=1:m
        for k=1:n
            c=coeff(p(l,k))
            knz=find(c<>0)
            if knz==[] then
                txt(2*l-1:2*l,k)=[" ";"0"];
            else
                c=c(knz)
                //special case for i=1
                if isreal(c(1),0) then
                    w=real(c(1))
                    if w<0 then
                        C(1)=" - "+string(abs(c(1))),
                    else
                        C(1)=string(c(1)),
                    end
                else
                    w=string(c(1));
                    if knz(1)<> 1 then w="("+w+")",end
                    C(1)=w;
                end

                for i=2:size(c,"*"),
                    if isreal(c(i),0) then
                        w=real(c(i))
                        if w<0 then
                            C(i)=" - "+string(abs(c(i))),
                        else
                            C(i)=" + "+string(c(i)),
                        end
                    else
                        C(i)=" + ("+string(c(i))+")";
                    end
                end

                if knz(1)>1 then
                    C=C+s
                else
                    C(2:$)=C(2:$)+s
                end

                i=min(find(knz>2))
                blank=" "
                e=blank(ones(1,i-1))
                if size(knz,"*")>=i then e=[e string(knz(i:$)-1)],end

                lc=cumsum(length(C))
                C=strcat(C)
                E="";
                for i=1:size(c,"*"),E=E+part(" ",1:(lc(i)-length(E)))+e(i);end
                txt(2*l-1:2*l,k)=[E;C];
            end
        end
    end
endfunction