Error using + Matrix dimensions must agree.

My code is below:

switch ForcingFunction
    case 1
      %F=FcosOmegat
      Theta=atan(2.*Z.*Omega_n*Omega./(Omega_n.^2-Omega^2));
      X=Ft./sqrt((Omega_n.^2-Omega^2).^2+(2*Z.*Omega_n.*Omega).^2);
      Phi=atan((Omega_d.*(x0-(X.*cos(Theta)))))./((v0+(x0-(X.*cos(Theta))).*Z.*Omega_n)-(Omega.*X.*sin(Theta))));
      Phi(isnan(Phi<thresold & Phi>-thresold))=0;
      A_UP=(x0-X.*cos(Theta));
      A_DOWN=csc(Phi);
      A_DOWN(A_DOWN<thresold & A_DOWN>thresold)=0;
      A=A_UP./A_DOWN;
      for n=1:3,
          RT(n,:)=A(n)*exp(-Z(n).*Omega_n(n).*t).*sin(Omega_d(n).*t+Phi(n))+X(n).*cos(Omega*t-Theta(n));
      end

    Error using  - 
  Matrix dimensions must agree.
  Error in new>CalculatingEquations (line 1064)
            Phi=atan((Omega_d.*(x0-(X.*cos(Theta)))))./((v0+(x0-(X.*cos(Theta))).*Z.*Omega_n)-(Omega.*X.*sin(Theta)));
  Error in new>calc_button_Callback (line 874)
  CalculatingEquations(hObject, eventdata, handles);

However I always got an error when calculating Phi in all cases but X and Theta are fine even case 2 and case 3 are similar to case 1.

In this case I am trying to calculating three RTs

Note that :

Omega_d,x0,X,Theta,v0,Z,Phi,A are and should be [3x1] matrices like [1;2;3]

t is time ,t=ti:interval:tf

Omega is a constant, for example 20

On the other hand, if I seperate the whole work from GUIDE program, ie just run the script the code is absolutely fine. I can get the correct results

[Walter Roberson]

At the MATLAB command prompt give the command

dbstop if error

and run the program. When it stops, examine the size() of each of the variables.

v0 looks to me to be the most likely to be the unexpected size.