function[]=plot_legend(num)
%
if(num==1)legend('dof 1'); end
if(num==2)legend('dof 1','dof 2'); end
if(num==3)legend('dof 1','dof 2','dof 3'); end
if(num==4)legend('dof 1','dof 2','dof 3','dof 4'); end
if(num==5)legend('dof 1','dof 2','dof 3','dof 4','dof 5'); end
if(num==6)legend('dof 1','dof 2','dof 3','dof 4','dof 5','dof 6'); end