Sparse jacobian: inf's and nan's in non-zero values array

[svigerske]

Issue created by migration from Trac.

Original creator: ad007804

Original creation time: 2013-03-22 13:15:11

Assignee: @awalther1

Version:

Keywords: sparce jacobian

Hi,

I am a new user of the ADOL-C library.

I am trying to solve the jacobian of a residual function in my structured CFD solver. In my application, I have 5 dependent variables and roughly 1700 independent variables. The number of non-zero values in the jacobian matrix is roughly 200, hence the usage of the sparse_jac driver.

The jacobian driver works perfectly fine, but I obtain inf's and nan's in the non-zeros values array. Note that the row and column index arrays are fine when compared to the entire matrix output of the jacobian driver. I tried changing the option array without success.

I was using version 2.3.0 and recently upgraded to 4.3.1 with the same behavior.

Can you please help me with my problem?
Thank you for your time,
Antoine

[svigerske]

Comment by ad007804 created at 2013-03-22 13:20:11

BTW, I am using colpack version 1.0.9.

[svigerske]

Comment by ad007804 created at 2013-03-22 15:31:48

Me again!

I solved my problem by changing the following:

WAS:
pow(fabs(spi)),zeta);

IS:
pow(fabs(spi)+epsilon,zeta);

Is this a best practice I should apply for all fabs?