How to see modal analysis calculation (computation)

[nabildhiyaulhaq]

I've modeled a simple 2 DOF structure in ETABS then manually computed the modal analysis
I used mass story and story stiffness on ETABS data table
but when i compared my manual computation eigenvalue with ETABS eigenvalue, they both not the same
i'm really sure that my manual calculation is correct, can you please help me to find the ETABS modal analysis calculation?

simple 2 DOF structure -> 2 story shear building (only Ux or Uy analysis direction activated)

I found that this only occur if i run model analysis in 3 dimension structure

i've made 2 dimension frame and run modal analysis on it, and the eigenvalue from my manual calculation with program calculation are same

 

[nabildhiyaulhaq]

solved

 

[huangenping]

Can you explain what is the problem and how you solve it?