%**************************************************************************
%       MontaKg 
%
%       numbering ==  1: Plota a malha em preto com os nós e elementos
%                               0: Plota a malha em preto somente
%
%       inci(numero, tipo, tmat, tgeo, no1, no2 ,...)
%       coord( x1,y1; x2,y2 ; ...)
%
%   Author: Renato Pavanello
%   Copyright (c) 2023 by The DMC/FEM/UNICAMP.
%**************************************************************************
function [kg]=montaKg(coord,inci,Tgeo,Tmat,nnos,nel)
%   Assemblage of global  stiffness matrix 
kg=zeros(2*nnos);

for e = 1:nel
     noi=inci(e,5);    
     noj=inci(e,6);
     xi=coord(noi,1);
     yi=coord(noi,2);
     xj=coord(noj,1);
     yj=coord(noj,2);
     l=sqrt((xj-xi)^2+ (yj-yi)^2);
     c=(xj-xi)/l;
     s=(yj-yi)/l;
     E=Tmat(inci(e,3) ,1);
     A=Tgeo(inci(e,4) ,1);
          
     ke= (E*A/l)*[ c^2      c*s    -c^2   -c*s;
                   c*s      s^2    -c*s   -s^2;
                  -c^2    -c*s     c^2    c*s;
                  -c*s    -s^2     c*s     s^2];
     
     loc=[2*noi-1   2*noi  2*noj-1   2*noj];
     kg(loc,loc)=kg(loc,loc)+ke;
end