Did you set preallocation values when you created the matrix? Don't do that. On Wed, Dec 20, 2023 at 9:36 AM Shatanawi, Sawsan Muhammad < [email protected]> wrote:
Hello,
I am trying to create a sparse matrix( which is as I believe a zero matrix) then adding some nonzero elements to it over a loop, then assembling it
Get Outlook for iOS <https://aka.ms/o0ukef> ------------------------------ *From:* Mark Adams <[email protected]> *Sent:* Wednesday, December 20, 2023 2:48 AM *To:* Shatanawi, Sawsan Muhammad <[email protected]> *Cc:* [email protected] <[email protected]> *Subject:* Re: [petsc-users] Help with Integrating PETSc into Fortran Groundwater Flow Simulation Code
*[EXTERNAL EMAIL]* I am guessing that you are creating a matrix, adding to it, finalizing it ("assembly"), and then adding to it again, which is fine, but you are adding new non-zeros to the sparsity pattern. If this is what you want then you can tell the matrix to let you do that. Otherwise you have a bug.
Mark
On Tue, Dec 19, 2023 at 9:50 PM Shatanawi, Sawsan Muhammad via petsc-users <[email protected]> wrote:
Hello everyone,
I hope this email finds you well.
My Name is Sawsan Shatanawi, and I am currently working on developing a Fortran code for simulating groundwater flow in a 3D system. The code involves solving a nonlinear system, and I have created the matrix to be solved using the PCG solver and Picard iteration. However, when I tried to assign it as a PETSc matrix I started getting a lot of error messages.
I am kindly asking if someone can help me, I would be happy to share my code with him/her.
Please find the attached file contains a list of errors I have gotten
Thank you in advance for your time and assistance.
Best regards,
Sawsan