Si2:Aula2

N =10; x1=-2; x2= 2; y1=-2; y2= 2;

for i=1:N

 for j=1:N
   r = (i-1)/(N-1);
   s = (j-1)/(N-1);    
   x(i,j)=x1 *r + x2*(1-r);
   y(i,j)=y1 *s + y2*(1-s);

   xv(i) =x(i,j);
   yv(j) =y(i,j);
   z(i,j)=1-x(i,j)-y(i,j);
 end

end

surf(x,y, z,'facecol','interp')

fig = gcf(); fig.color_map=coolcolormap(32); contour2d( xv,yv, z,20)