function [ObjV]=objfuncGA(x,Xobs,Yobs,Zobs,Uxoss,Uyoss,Uzoss,ForwardModel,ni) 

 
% You can enter the objective function



SourceType=ForwardModel(1);

U_obs=[Uxoss, Uyoss, Uzoss];  % row vector of observed values 
U_obs=U_obs'; % column vector of observed values  
  



switch SourceType
    
      
    case 1 % sphere
        Xc=x(1);
        Yc=x(2);
        Zc=x(3);      
        DeltaV=1; % least squares     
        [Ux_calc,Uy_calc,Uz_calc]=deformation_sphere(Xobs,Yobs,Zobs,Xc,Yc,Zc,DeltaV,ni); % row vectors of computed deformation


    case 2 % rectangular prism
        SourceRotation=ForwardModel(2);
        Xc=x(1);
        Yc=x(2);
        depth=x(3);
        l_a=x(4);
        l_b=x(5);
        l_c=x(6);
        if SourceRotation==1 % yes rotation
            alpha=x(7);
            delta=x(8);
            gamma=x(9);
        else 
            alpha=0;
            delta=0;
            gamma=0; 
        end
        eps_0=1; % least squares  
        [Ux_calc,Uy_calc,Uz_calc]=deformation_prism(Xobs,Yobs,Zobs,Xc,Yc,depth,l_a,l_b,l_c,alpha,delta,gamma,eps_0,ni); % row vectors of computed deformation


    case 3 % prolate or oblate ellipsoid
        SourceRotation=ForwardModel(2);
        Xc=x(1);
        Yc=x(2);
        depth=x(3);
        a=x(4);
        b=x(5);
        if SourceRotation==1 % yes rotation
            alpha=x(6);
            delta=x(7);
            gamma=x(8);
        else 
            alpha=0;
            delta=0;
            gamma=0; 
        end        
        eps_0=1; % least squares  
        [Ux_calc,Uy_calc,Uz_calc]=deformation_prolate_oblate_ellipsoid(Xobs,Yobs,Zobs,Xc,Yc,depth,a,b,alpha,delta,gamma,eps_0,ni);  % row vectors of computed deformation


    case 4 % triaxial ellipsoid
        SourceRotation=ForwardModel(2);
        Xc=x(1);
        Yc=x(2);
        depth=x(3);
        a=x(4);
        b=x(5);
        c=x(6);
        if SourceRotation==1 % yes rotation
            alpha=x(7);
            delta=x(8);
            gamma=x(9);
        else 
            alpha=0;
            delta=0;
            gamma=0; 
        end        
        eps_0=1; % least squares  
        [Ux_calc,Uy_calc,Uz_calc]=deformation_triaxial_ellipsoid(Xobs,Yobs,Zobs,Xc,Yc,depth,a,b,c,alpha,delta,gamma,eps_0,ni);  % row vectors of computed deformation


    case 5 % cylinder       
        Xc=x(1);
        Yc=x(2);
        rho_radial_obs=sqrt((Xc-Xobs).^2+(Yc-Yobs).^2); % radial distance between source and observation points
        depth=x(3);
        R=x(4);
        h=x(5);
        eps_0=1; % least squares
        [Ur_calc,Uz_calc]=deformation_cylinder(rho_radial_obs,Zobs,depth,R,h,eps_0,ni); % row vectors of computed deformation    
        % x and y components of radial deformation
        Ux_calc=Ur_calc.*(Xobs-Xc)./rho_radial_obs;  % row vector 
        Uy_calc=Ur_calc.*(Yobs-Yc)./rho_radial_obs;  % row vector

end

  
U_calc=[Ux_calc,Uy_calc,Uz_calc]; % row vector of computed deformations
U_calc=U_calc'; % column vector of computed deformations
           
param=inv(U_calc'*U_calc)*U_calc'*U_obs; % parameter of the least square
          
Ux=Ux_calc*param; % row vector
Uy=Uy_calc*param; % row vector
Uz=Uz_calc*param; % row vector


% objective function 
ObjV = sqrt(  1/(length(Uxoss) + length(Uyoss) + length(Uzoss)) * (sum((Uxoss-Ux).^2)  +  sum((Uyoss-Uy).^2)  +  sum((Uzoss-Uz).^2))   );