function [pmode,xvv]=plot_modes(ibc,mode,dof,dx)
%
disp(' ');
dof_half=round(dof/2);
%
for j=1:dof_half
%
    aq = sprintf(' Plot Mode %d ?',j);
    disp(aq);
    choice=input(' 1=yes  2=no  3=exit  ' );
%
%   
    if(choice==3)
        pmode=zeros(dof_half);
        xvv=zeros(dof_half);     
        break;
    end
    if(choice~=3)
      
    if(choice==1)
    at = sprintf(' Mode %d ',j);
    if(ibc==1)
        for i=1:dof_half
            pmode(i)=mode(2*i-1,j);
        end
        xv(1)=0.;
        for i=2:dof_half
           xv(i)=xv(i-1)+dx(i-1);    
        end
    end
    if(ibc==2)
        pmode(1)=0.;
        xv(1)=0.;       
        for i=1:dof_half
            pmode(i+1)=mode(2*i-1,j);
            xv(i+1)=xv(i)+dx(i);            
        end
    end
    if(ibc==3)
        pmode(1)=0.;
        xv(1)=0.;          
        for i=1:dof_half
            pmode(i+1)=mode(2*i-1,j); 
            xv(i+1)=xv(i)+dx(i);              
            pmode(i+2)=0.; 
            xv(i+2)=xv(i+1)+dx(i+1);    
        end
    end
    if(ibc==4)
        pmode(1)=0.;
        xv(1)=0.;       
        for i=1:(-1+(dof_half))
            pmode(i+1)=mode(2*i,j); 
            xv(i+1)=xv(i)+dx(i);        
            pmode(i+2)=0.; 
            xv(i+2)=xv(i+1)+dx(i+1);        
        end
    end
%
    figure
    xvv=xv;
    plot(xvv,pmode) 
    grid;
    set(gca,'MinorGridLineStyle','none','GridLineStyle',':','XScale','lin','YScale','lin');    
    title(at);
    xlabel('x (inch)'); ylabel('displacement');
    end
    end
end