function[fig_num]=two_dof_frf_apply_sine(omg12,omg22,damp1,damp2,omg1,omg2,MS,n1,n2,fig_num,iu)
%
fig_num=fig_num+0;
disp(' ');
disp(' Apply steady-state sine vibration base input? ');
disp(' 1=yes  2=no ');
isine = input(' ');
%
if(isine==1)
    tpi=2*pi;
    disp(' ');
    disp(' Enter frequency (Hz) ');
    freq=input(' ');
    disp(' ');
    disp(' Enter amplitude (G) ');
    amp=input(' ');
%
%
    clear omega;
    clear om2;
    clear D1;
    clear D2;
    clear N1;
    clear N2
    clear aaa;
    clear bbb;
%
    omga=tpi*freq;
    om2=omga^2;
%
    D1=(omg12-om2)+i*(2*damp1*omg1*omga);
    D2=(omg22-om2)+i*(2*damp2*omg2*omga);
%
    N1=om2*n1/D1;
    N2=om2*n2/D2;
%
    aaa= 1 + ( MS(1,1)*N1 + MS(1,2)*N2);
    bbb= 1 + ( MS(2,1)*N1 + MS(2,2)*N2);
%
    H1_sine=abs(aaa);
    H2_sine=abs(bbb);
%
    ZN1=n1/D1;
    ZN2=n2/D2;
%
    aaa= -( MS(1,1)*ZN1 + MS(1,2)*ZN2);
    bbb= -( MS(2,1)*ZN1 + MS(2,2)*ZN2);
%
    ZH1_sine=386*abs(aaa);
    ZH2_sine=386*abs(bbb);
    ZH3_sine=386*abs(bbb-aaa);
%
%
    mass1_acc=H1_sine*amp;
    mass2_acc=H2_sine*amp;
%
    mass1_rd=ZH1_sine*amp;
    mass2_rd=ZH2_sine*amp;
    mass21_rd=ZH3_sine*amp;    
%
    out1=sprintf(' mass 1: %8.4g G  ',mass1_acc);
    out2=sprintf(' mass 2: %8.4g G  ',mass2_acc);
    out3=sprintf(' mass 1: %8.4g in  ',mass1_rd);
    out4=sprintf(' mass 2: %8.4g in  ',mass2_rd); 
    out5=sprintf(' mass 2 - mass 1 : %8.4g in  ',mass21_rd);  
%
    disp(' ');
    disp(' Acceleration ');
    disp(out1);
    disp(out2);
% 
    disp(' ');
    disp(' Displacement Relative to Base ');    
    disp(out3);
    disp(out4);
%
    disp(' ');
    disp(' Displacement Mass 2 relative to Mass 1 ');    
    disp(out5);
%    
end
%