Help Error using eig Input to EIG must not contain NaN or Inf

Error using eig
Input to EIG must not contain NaN or Inf.

Error in composite_twoshaft_spurgear (line 450)
   w=sort(abs(imag(eig(EF))));

   E=[o,-(MM1+MM2+MMd);(MM1+MM2+MMd),(CC1+CC2+CCB1+CCB2)+(Oma1*(GG1+GGd1)+Oma2*(GG2+GGd2))];
   F=[(MM1+MM2+MMd),o;o,(KK1+KK2+KKB1+KKB2)];
   EF=-inv(E)*F;
   w=sort(abs(imag(eig(EF))));
   ww(:,n)=w;
   [C,D]=eig(EF);

[KSSV]

To calculate eigenvalues of a given matrix, there must be no Nans or inf. Your matrix EF have Nan's . Check it.

[Walter Roberson]

Use

EF =-E\F

However your matrix might simply not be invertible

[Walter Roberson]

If your values have multiple inf, or if one contains inf and the other contst least one 0, or if your values for E are all 0, then you will get nan results. If your E is not invertible otherwise then I do not recall if you get inf or nan as the result.

[Walter Roberson]

Note to respond, click on "Comment on this" not on Flag. Flag is for pointing out a problem to the moderators such as if you notice a spam message.

[Cheng Xu Feng]

I check my EF are 408x408 matrix but all of elemenets are Nan. I don't know how to slove? I have 6dof problem.

[KSSV]

So problem is with MM1 etc values. You have to show us the complete code to solve the problem.

[Walter Roberson]

Please show the output of

rcond(E)
rank(E)
rank(F)
nnz(~isfinite(E))
nnz(~isfinite(F))

Answer 1

[Cheng Xu Feng]

I already solve this problem. but ans are wrong.

[Walter Roberson]

How do you know they are wrong?

What is your current code? What are

rcond(E)
rank(E)
rank(F)
nnz(~isfinite(E))
nnz(~isfinite(F))

[laiche zeghdi]

i have same problem . can you help me

1) An error occurred while running the simulation and the simulation was terminated

Caused by: Input to EIG must not contain NaN or Inf.

2) Cannot create variable 'if' in workspace Caused by:

ASSIGNIN cannot assign to variables with the same name as a MATLAB keyword