FEAP User Forum

FEAP => Programming => Topic started by: jucavel09 on July 02, 2021, 09:31:44 AM

Title: Accesing Arrays after EigenValue Calculation
Post by: jucavel09 on July 02, 2021, 09:31:44 AM

Hello,

I've been working on a particular application where I need access to the set of eigenvalues, eigenvectors, tangent, and mass matrices after solving a frequency analysis. Do you know where can I get access to those arrays, because I need to do some calculations with them in an additional subroutine?. Using the OUTput option is not an alternative in my case, I would like to have direct access to the arrays.

Thank you

Title: Re: Accesing Arrays after EigenValue Calculation
Post by: Prof. R.L. Taylor on July 02, 2021, 01:27:40 PM

The eigenvalues are in EVAL and the eigenvectors in EVEC.  Use the command SHOW DICT to see allocated arrays.  Use SHOW EVAL will display the values.  You need to write a user module to get the values and process as you need.

Read programmer manual on how to access the arrays in hr(*)  for your  module.

Note that the eigenvectors store only the non-zero values.  Values on restrained dof's are zero.

Title: Re: Accesing Arrays after EigenValue Calculation
Post by: Prof. S. Govindjee on July 02, 2021, 06:20:19 PM

Also note that after solution you will have the factored tangent matrix in FEAP's arrays.